Friday, May 28, 2010

Mounting a Scope

Sometimes it seems that nothing is more confusing to a new gun owner, and even some old hats, as installing a scope on a firearm. The sheer number of choices and options in optics alone are enough to write books about, and the ways to actually put the scope on the gun are even more complicated.

This article will attempt to clarify choices and make the novice gun owner’s job in choosing a way to mount a scope easier, while at the same time illuminate the myriad of options for any gun owner.

What You Need to Know (or Find Out)
When you start looking to mount a particular scope on your firearm you need to know certain things before you start shopping for mounting options. To begin with, you’ll need to know your scope’s objective diameter, usually the last and largest number in a scope’s specifications. This will be used to determine the clearance needed for your scope. The next important measurement you’ll need is the scope tube, and thus what ring diameter is required by your scope, usually 1″ or 30mm.

You need to know what mounting system your rifle is equipped with; receiver grooves, Picatinny rail, Weaver dovetail base, or nothing at all. The type of firearm you have and in some cases, what barrel type and contour, will also impact what mounting system you will need to use. A flat-top AR-15 has vastly different ring requirements than a Remington 700 with a tapered barrel.

The Basics
The most common setup used, and inquired about, for putting optics on a long gun is mounting a traditional magnified rifle scope to a traditional bolt action rifle. Let’s use this setup to explore the basics of putting a scope on a rifle. Traditionally the scope is held onto the rifle by “rings” which are clamped around the body of the scope. In turn the rings are attached to some sort of “base”, which are normally then attached to the rifles receiver or action.

To add to the confusion, there are many variations of all of these components. There are ways mount a scope that combine some or even all of these individual components. (An example would be mounting an EOtech HWS to an AR-15 rifle, where the scope has an integral mount that does not require rings, and the rifle has an integral rail that does not require a base.)

The base is the part of the system that allows the attachment of the scope rings to the rifle itself. Traditionally bases are attached to the receiver of a firearm by some sort of screw or bolt. Some rifles have built-in bases that are integral to the firearm.

Bases are usually specific to the make and model of firearm for which they are designed, and most are specific to the type of rings that can be used with them.

The Ring you select must be the same inner diameter of your scope’s tube diameter, which makes sense. The rings clamp onto the main tube of the scope, so they must be the same size. Most scopes are 1 inch in diameter and so are most rings, but there are many 30mm scopes and rings, and a smattering of other choices, such as 34mm. The other end of the ring attaches to the rifle’s base, so it too must be compatible with that particular base.

The important thing to remember is to match the rings with the scope and the base.

Ring Height
Scope rings come in varying heights to vary the distance from the scope’s centerline to the firearm’s base or receiver. The different ring heights allow you to mount scopes with different objective sizes and also to mount the scope in the proper place for a quick and proper cheekweld. Rings normally come in low, medium and high heights. There are extra low and extra high variations from some manufactures. Ring height is one of the most confusing options for new gun owners.

The traditional mantra is that scopes should be mounted as low as possible without the front of the scope, the objective bell housing, touching the barrel. Also bearing in mind the need to the back of the scope, the ocular bell or eyepiece, to clear the bolt handle. The thing most often ignored in this choosing scope ring height is the need for the scope’s height to match the shooter. When the rifle is shouldered quickly, the scope should be at the correct height to look through it, without any additional movement on the stock up or down to get a good view through the scope.

Remember though that there is no “perfect” ring height that would suit every person, as each person’s physiology is a little bit different. There is a standard ring height worth noting, as it gives an excellent starting point for 90% of gun owners.

In this illustration from UTG, Ring height is measured with “C”

Ring Height According to Leupold

  • 50mm objectives will almost always use HIGH rings in a given style. In certain instances, such as with extremely heavy barrels or some makes of firearm, EXTRA HIGH rings may be necessary.
  • 42-45mm objectives will almost always use MEDIUM rings in a given style. In certain instances, 45mm scopes may require HIGH rings.
  • 40mm objectives will almost always have enough clearance with LOW rings in a given style, though MEDIUM rings will give slightly more clearance, particularly when using a barrel with a thicker shank portion or a heavier contour.
  • 28-36mm objectives will almost always use LOW rings in a given style. Again, in certain instances of a heavy barrel or heavy shank portion of a custom barrel, MEDUIM rings may have to be used, but LOW rings will almost always suffice.
  • 20-24mm objectives will almost always be able to use LOW rings, but in some cases may also use EXTRA LOW rings. In this instance, bolt handle clearance of the eyepiecel will come into play more so than objective / barrel clearance and should be carefully considered.

No Leupold riflescope will fit into EXTRA LOW rings if using a one-piece base.

Ring Height According to Weaver

  • Use low 1″ Rings for up to a 38mm Scope Objective
  • Use medium 1″ Rings for up to a 40mm Scope Objective
  • Use high 1″ Rings for up to a 44mm Scope Objective
  • Use extra high 1″ Rings for up to a 50mm Scope Objective
  • Use 30mm Low Rings for up to a 33mm Scope Objective
  • Use 30mm high Rings for up to a 44mm Scope Objective

For a more in depth look at ring height click here to refer to our ring height article.

Now that we have discussed ring height standards, there are some notable exceptions: for the AR-15 and M-4 series of rifles with “flat top” receivers extra-high rings are the rule of thumb, but some applications use high rings. Also, for mounting a scope on a Harrington and Richardson Handi-Rifle or the NEF Pardner you will need at least medium and perhaps high rings clearance between the scope’s eyepiece and the rifle’s hammer.

Mounting Systems
The most common scope mounting system is the Weaver system. The weaver system utilizes flat dovetail rails with crosswise slots found on everything from rifles to shotguns to handguns. The Weaver style bases are 7/8 inch wide and are designed to accept Weaver style rings. Most rings manufacturers make a Weaver style ring and/or rail. On Weaver style rings the bolt used to secure the ring runs underneath the web of the ring and fits into a corresponding crosswise slot in the Weaver base. This prevents any scope movement fore and aft under recoil or abuse. The bases can be found in one or two piece configurations and can be made of steel or aluminum. The Weaver style system allow the Weaver ring to be detached from the base with the scope still in the rings and reattached without any major loss of zero. The optic can be removed from the gun for maintenance, transportation or storage. The weaver system also allows for using different optics on one weapon or one optic on different weapons.

Picatinny and MIL-STD-1913
Picatinny rails are very similar to Weaver rails. The difference is a published military standard. The physical difference between Weaver rails and Picatinny rails are the width of the slots that are cut crosswise in the base, and the spacing of these slots. The slots in Picatinny bases are wider than slots in a Weaver base, and the spacing of these slots in a Picatinny rail is consistent and standardized. The Weaver style rail’s spacing of the cross slots are not standardized and the spacing is left up to the manufacturer. The recoil lugs on Picatinny rings are thicker to fit in the corresponding wider slots in the Picatinny bases. Weaver rings will fit on Picatinny bases, but Picatinny rings won’t fit on Weaver bases.

22 Rimfire Rings, Tip-Off Rings and 3/8″ Dovetail Rings
Most .22 rimfire rifles and airguns produced today have cuts running lengthwise in the top of the receiver to mount rings on. Some European .22s and air rifles have grooves that measure 11mm or 13mm. 3/8″ dovetail rings are clamped into the groove of these grooved receivers, these rings are also referred to as rimfire rings, .22 rings, and Weaver brands them Tip-Off rings. There are also rifle found with 3/8″ bases attached to the receiver with screws as a normal base would be, and you can buy 3/8″ bases to add to most firearms without them. Some rifles with a grooved receiver are drilled and tapped for Weaver style bases. We recommend using a Weaver style base in these cases as they offer more area for the rings to grab and are more secure and stable.

Redfield Style
The second most common mount type is the Redfield style. This type of mounting system, like the Weaver, has many clones and manufactures of bases and rings. The bases can be one or two pieces, and are known for their sleekness, and strength. Unlike Weaver style rings, Redfield style rings are not detachable from the rails system. The top half of the rings must be separated from the bottom half to remove your scope. The front ring in the Redfield system has a dovetail that turns into a corresponding slot in the front base, allowing the scope to pivot around this point. The rear ring in the Redfield system sits on the base and is held by two opposing windage screws tightened into the ring. The windage screws have a leading edge that fit a corresponding slot in the ring. By loosening out one screw and tightening the other, the ring moves right and left on the base, acting as an external adjustment. This adjustment allows you to zero the windage of your scope without using its internal adjustments.

Dual Dovetail (DD) Systems
Dual dovetail bases are the same as Redfield style, but instead of the windage screws holding the rear ring to the base, the rear ring is turned in just like the front. This system does not offer the windage adjustments that the standard Redfield style bases offer. This system is secure and a very strong system for heavy recoiling rifles and handguns.

Clamp-on Mounts
Clamp on mount such as made by B-Square, S&K, ATI and other manufacturers allow easy scope mounting on guns that aren’t drilled and tapped for scope mounts. These mounts typically do not require gunsmithing, and are easily removed without any modifications to the firearm. Older and military surplus firearms often benefit greatly with these style mounts.

Thursday, May 27, 2010

Shooting Steel Cased Ammunition In Your AR-15

If you’ve been shooting for very long, especially as ammunition prices have risen in the past two years, you’ve no doubt noticed the large amount of inexpensive steel cased ammunition available. It’s hard to pass it up: prices for steel cased ammunition are almost half that of traditional brass cased ammo. But take it out to the range and it won’t be long before you hear the “tsk tsk” of other shooters, shaking their heads and commenting on how horrible it is to run steel cased ammunition in an AR-15 style rifle.

But is steel cased ammo really so bad? Is it safe to shoot steel cased ammunition in your AR-15?

Let’s own up to a few facts first. Discount steel cased ammunition is, in general, dirtier and smellier than mil-spec Lake City manufactured 5.56 NATO ammunition. It’s not quite as accurate, but most shooters won’t miss a half-MOA here or there.

Now, on to some myth busting. Modern production steel cased ammunition is NOT corrosive, even when berdan primed. It won’t destroy your extractor, and it won’t accelerate wear on your bore. The ferrous bi-metal jackets found on most steel cased ammunition will not damage the rifling of your AR, and are perfectly safe to use on any rifle rated backstop.

So what do you need to do to run steel cased ammunition in your AR-15? First, you’ll need to make sure that your AR-15 is very well lubricated. Dripping wet some might say; especially the bolt carrier group. You’ll need to clean your rifle more often when shooting steel cased ammunition, at least once every 500 rounds, although you could get away with letting it go for up to 1,000 rounds. Because steel cased ammunition results in more carbon build up, it’s important to use a high quality solvent like M-Pro 7 along with a synthetic lubricant. Make sure to throughly clean your bolt, paying close attention to the bolt face and extractor. It’s usually a good idea to remove the extractor to clean underneath as well. You’ll also need to make sure to thoroughly clean the chamber, so picking up an M16/AR-15 chamber brush is a good idea.

Steel cased ammunition is generally loaded lighter than standard military loads, so it’s important that your gas system runs well. Some AR rifles have smaller gas ports and won’t cycle well with the reduced power loads found in some steel cased ammunition. If you find this is a problem, switching to higher power steel cased ammunition such as our Wolf Military Classic may resolve this issue. Using a lower weight buffer or a lighter buffer spring can also be necessary when shooting steel cased ammo.

Steel cased ammunition is available with three different types of coatings. Older steel cased ammunition was usually found with a lacquer finish to help prevent rust and corrosion of the case. Brown Bear ammunition still uses this coating. Some AR-15 rifles begin to have problems with lacquer coated steel cased ammunition as heat begins to build up. Switching to modern production steel cased ammo with polymer coatings sometimes alleviates this problem, but in other cases it is necessary to use zinc coated steel cased ammunition such as Silver Bear.

The best way to avoid extraction problems due to stuck cases is to use an AR-15 with a 5.56mm chamber. Differences in headspacing between 5.56 and .223 chambers can cause steel cased .223 or 5.56mm ammunition to get stuck as the metal heats up. Even Wylde chambers and other .223/5.56 hybrid chambers have been known to have issues with stuck spent steel casings. Stick with a true 5.56mm chamber and, as we mentioned above, remember to scrub the chamber out every 500-1000 rounds to ensure reliability.

Steel cased ammo may have gotten a bad rap in the past, but there’s really nothing wrong with it. So go for it! Some AR snobs may sneer at the mere thought of running steel cased ammo through their precious rifle, but you know better now. Save some money when plinking and try out steel cased ammunition. Most AR-15 rifles run it just fine with no problems at all.

Wednesday, May 26, 2010

Entry Level Bolt Action Rifles

It used to be that precision bolt action rifles were firearms that you had to save your pennies in order to be able to afford. In the past few years however, the price of an entry level bolt gun has fallen to the point that almost anyone can afford to purchase a high quality accurate rifle. In many cases, a durable 3-9x40mm scope is also included in the package allowing new shooters and first time hunters to get outfitted and up and running quickly. Here is a rundown of some of the best values we've found among entry level bolt action rifles.

Stevens 200
Savage has a line of entry-level rifles that are marketed under the Stevens brand. These rifles have been around for decades and became quite well known when the Stevens line was sold through popular mail order catalogs such as Sears and Montgomery Ward. Savage later purchased the Stevens brand, standardized their parts and incorporated the rifles into their line up as budget-model firearms.

The Stevens 200 rifle uses standard Savage Model 10/110 parts, making it easy to fix up and maintain. New, it is slightly more expensive than the Savage Edge, but significantly less than the 110. If you're looking to save a buck on an entry level deer rifle and are willing to put a little work into it, you can't go wrong searching gun shows and pawn shops for a well used Stevens 200 rifle. Given the abundance of Savage 110 parts, it is fairly easy to rebarrel and fix up an older Stevens 200.

Brand new, the Stevens 200 is obviously a budget entry-level rifle. It's not as finely finished as the more expensive 110, the stock is light weight and feels somewhat flimsy, but it has performance where it counts. The Stevens 200 shoots just fine right out of the box, easily grouping 2" or less at 100 yards. The bolt action is smooth without any binding, and the trigger is crisp and smooth with minimal overtravel. The Stevens 200 is available ready for you to mount the optic of your choice, or you can get it with a factory mounted scope in the 200 XP line.

Mossberg 100 ATR
The Model 100 ATR rifle from Mossberg is largely based off of the Japanese built Howa 1500 action. This simple to use rifle has only minimal controls: bolt, safety, and bolt release. Unlike most other budget rifles, the ATR has an internal box magazine. Its 4 round capacity allows the rifle to hold a total of 5 rounds with one in the chamber. The polymer stock is tough enough to stand up to harsh field conditions while still light enough to make this 7 pound rifle easy to carry on long stalks. Sling inserts are molded directly into it the stock, making it simple to attach swivels and a sling or bi-pod.

The "keep it simple" design used on the ATR makes it easy to quickly learn the controls well enough to operate by touch, allowing the shooter to keep their eyes on the target and not fumble around searching for the safety. It can be found new for around $300-$350 with a scope and is available chambered in .308, .243, .30-06, and .270 Winchester.

Mossberg 4x4
The newer Mossberg 4x4 is a step up from the ATR. While much nicer than the ATR, the 4x4 is not that much more expensive, with pricing right around $450 depending on how it is configured. It is chambered in .25-06, .270, .30-06, 7mm Remington Magnum, .300 WinMag, and .338 Winchester Magnum and has a detachable box magazine which holds four standard or three magnum cartridges.

The highlight of the 4x4 is in the action. The LBA "lightning" trigger breaks right around 3.5 lbs as set from the factory and is user adjustable down to a very light 2 pounds. The bolt moves effortlessly and locks securely into place with two lugs. The two position safety placed just behind the bolt handle blocks the trigger but still allows the bolt to be opened with the safety "on".

The 4x4 is available with a wide range of stock and barrel combinations. Mossberg's futuristic looking skeletonized stock can be had in synthetic or laminate, while walnut stocks are offered in a sculpted style similar to the skeletonized stock or in a traditional classic design. All of the stocks offered have a Monte Carlo style raised cheek piece built in to better position the shooter and enhance cheek weld. Barrels can be found tapered or fluted with a traditional blue matte finish, or with Mossberg's proprietary Marinecoat stainless satin finish. Ported muzzle breaks are also available to help reduce recoil.

Marlin XL7
There's nothing particularly special about the XL7. It's a fairly plain bolt action rifle built around tried and trued designs. But don't let that dissuade you from buying one. Marlin engineers took a proven bolt action design and refined it until they came up with the XL7, a rifle that is supremely accurate as well as reliable. The Marlin XL7 comes with a Pro-Fire adjustable trigger system. The Pro-Fire system is fully adjustable by the user, and incorporates a trigger safety to help prevent accidental discharges. Additional safety devices include a standard 2 position safety located behind the bolt handle and red indicator behind the bolt for a visual indication that the rifle is cocked. A fluted bolt makes the action very easy to quickly open and close, and the bolt movement itself is silky smooth.

Like the Mossberg ATR, it utilizes an internal box magazine which holds 4 long action cartridges. Though it does not include a scope, the Marlin XL7 does come with a one piece scope base.

The XL7 is available in .25-06, .270, and .30-06. and dealer prices for the XL7 range from $300-$400.

Remington 770
Well known rifle manufacturer Remington made quite a reputation for themselves with their line of Model 700 rifles. Available in a wide range of configurations and finishes, the Model 700 is easily the best selling bolt action rifle in the world. Variants of the Model 700 are the rifle of choice for military and SWAT snipers.

The Remington Model 770 is an updated and much improved version of the Model 700 based 710 rifle. Improvements on the 710 design include a modified detachable magazine release, redesigned stock with raised cheek piece, and the addition of texturing to the grip. A mounted and boresighted 3-9x40 scope is included with every 770.

The Model 770 is available with a black synthetic stock and blued barrel, or in stainless with a Realtree patterned camouflage stock, and can be found in long action chambered for .30-06, .300 Remington Magnum, and .300 Winchester Magnum or short action chambered for 7mm-08 and .308 Winchester. A recent addition to the 770 line is the 770 Compact Model chambered in the mild recoiling .243 Winchester, making perfect for youth.

Savage Edge
By far the best bang for your buck, the Savage Edge features a silky smooth bolt and 22" Free-Floating Tapered Barrel topped with a matching 3-9x40mm scope. Dual pillar bedding further enhances the consistency of the barrel. It is only available in long action, but is able to handle both long and short action cartridges and can be found with a variety of calibers ranging from .223 Remington, .243 Winchester, .25-06, and .308, on up to .270 Winchester and .30-06. MSRP is set at $396, but dealer prices are hovering slightly over $300. The Edge's synthetic stock is available in your choice of black or camo.

The Savage Edge is not just a rehashed Savage 110. While there are similarities between the two designs such as the bolt head, the few differences such as the bolt handle are easy to spot. The new handle is a skeletonized version of the 110 bolt handle and adds some visual interest to the Edge. Like the 110, the bolt action on the new Edge is smooth and shows no indication of binding. It uses the same dual bolt lugs as the 110, the even pressure on the bolt face ensuring that the cartridge is perfectly aligned with the bore every time. Unlike the 110, the Edge uses a different action and trigger. Gone is the much loved Savage AccuTrigger, but don't despair. The Edge trigger is still a very nice crisp trigger with a "glass rod" break right at five pounds. While the new trigger is not adjustable, it can still be fine tuned by a gunsmith if desired.

Easily shooting 1.5 MOA, the Savage Edge is more than accurate enough to serve as a deer rifle. Any beginning hunter would do well to consider this rifle as a great starting point.

Whether you are an experienced hunter looking for the perfect beginner rifle for your young hunter or a new hunter looking for an inexpensive rifle to take your first deer, there is an entry level rifle out there that will fit your budget and your needs perfectly. Most of these rifles come factory equipped with a 3-9x scope, making it that much easier to get your firearm on target out in the field.

Tuesday, May 25, 2010

May E-Postal Match Deadline Approaching!

It’s almost the deadline for getting your entries in for the May E-Postal match hosted by Danno over at Sandcastle Scrolls. You’ve got a long Memorial Day weekend ahead of you to head out and shoot your target, so what’s holding you back? Each entry gives you a chance to win a $50 gift certificate from Cheaper Than Dirt!

Download Danno’s Dart Board Target, pack up your pistols or rifles, head out to the range and shoot your entry. When you’re done, scan or take a picture of your target and send it along with your name, blog or website URL, class, score, gun details (Make & Model, caliber, barrel length, sight system), and range shot at to sandcastlescrolls at msn dot com no later than 11:59 PM on Monday May 31st.

Click HERE to download your target (*.PDF)

E-Postal Contest rules are available here at Danno’s blog, Sandcastle Scrolls.

Friday, May 21, 2010

Concealed Carry - Pancake Holsters

Pancake holsters were initially designed by Roy Baker nearly 60 years ago as a flat-style carry holster that holds a handgun close to the body. Intended to be worn on the belt, either strong side or cross draw, Baker’s three-slot design is incredibly versatile allowing the wearer to position the pistol at differing angles depending on where the holster is worn. Two slot pancake holsters also are manufactured, but unlike three slot designs limit the angle and position at which the pistol can be carried. Most two slot pancake designs position the pistol best when worn on the strong side hip position.

A number of pancake designs exist on the market, most notably Safariland’s two slot pancake holster with thumb break retention strap and Bianchi’s Model 77 Piranha three slot pancake holster. The thumb-break retention strap on both of these models is reinforced for additional stiffness to help ensure an easy, clean and consistent break. Both models also feature custom boning specific to your model handgun which gives the holster enhanced retention. If you choose to go with a leather model that does not have a thumb-break retention strap, make sure that the holster is custom fitted for your particular firearm. Pancake holsters constructed of nylon instead of leather should always fit the pistol snugly and incorporate the use of a thumb-break strap.

How well a pancake holster fits depends largely on your body type, and like all concealed carry holsters, the pancake style is a compromise between comfort and concealability. In general, individuals with larger waistlines will find that pancake holsters suit them more than slimmer individuals. The design of the holster is intended to bring keep the pistol tight against your body, reducing the chance of “printing” and keeping the holster snugly in place. Pants that fit loosely will cause the holster to sag and the butt of the gun to be angled away from the body. Individuals with slimmer waistlines should look for pancake holsters that have the belt loops up high, bringing the butt of the gun in closer to the body while hanging the pistol barrel lower. Cover garments for these type holsters will need to be slightly longer in order to conceal the lower hanging pistol.

Pancake holsters are not without their drawbacks. First among these is the fact that donning or removing the holster requires that you remove your belt: there is no quick and easy way to take it on and off. Some manufacturers are beginning to make pancake holsters that have snap belt loops which allow the holster to be removed without taking off your belt, but these holsters are not yet readily available.

If you’re uncomfortable wearing IWB holsters and are looking for a different style of carry for your full size, compact, or sub-compact handgun, consider a pancake holster. They are available to fit most pistols and come in a variety of materials and colors.

Thursday, May 20, 2010

Handloading .223 for the AR

Military style rifles are not usually known for having match grade accuracy, but the AR-15 can be easily upgraded with just a few parts to be more than capable of shooting sub MOA groups out to distances exceeding 600 yards. Swap out the trigger for a Timney and replace the barrel with a heavy stainless steel varmint or match barrel and you'll be surprised by the significant increase in accuracy. But the biggest improvement may not come from the rifle at all, but from the ammunition you use.

I got started shooting cheap military surplus 5.56mm NATO rounds in my AR, along with cheap Winchester white box and Remington .223 FMJ plinking rounds. These cartridges were usually 55 or 62 grain and had decent accuracy. I still use them for plinking and just having fun at the range. But when you want to get serious about target shooting, you need better ammo. The biggest differences between mass produced ammunition and match grade ammunition is the quality of the components and the attention to detail to ensure every round is exactly the same.

Getting Started
You can buy match grade ammunition from a number of manufacturers. Remington and Hornady both manufacture excellent match grade ammunition. Varmint ammo from Remington and Hornady is just as accurate as the match grade ammunition, but is loaded with lighter bullets weighing between 40 and 55 grains. This factory ammunition is easily capable of shooting half-MOA groups is an excellent place to start establishing a baseline for your own handloads. Shoot a variety of loads and bullet weights to find out which performs best in your rifle and start loading your own based off of this data.

When selecting the proper bullet, keep your barrel twist in mind. We've written in the past on the importance of barrel twist rate with regards to bullet weight or, more accurately, bullet length. For any given caliber of ammunition, the heaver the bullet is the longer it will generally be. Longer bullets require a faster twist rate to get them spinning at a high enough speed for effective stabilization in flight. If there is a specific load you just have to run, consider rebarreling your rifle with a barrel with a more appropriate twist rate.

The first barrels produced by Colt for the AR-15 had a slow 1:14 twist rate, which was adequate for 55 grain bullets under normal circumstances. However when air density increased due to lower temperatures, the 55 grain became unstable. This prompted the Army to switch to a faster 1:12 rate barrel, and later an even faster 1:7 rate barrel to accommodate heavier 62 grain M855 bullets. Most modern rifles have a 1:9 twist rate, which has been found to be a healthy compromise that is able to stabilize bullets weighing from 50 grains on up to some 69 grain bullets.

Varminters often use very light weight bullets such as the 40 grain Sierra Hornet. Such bullets are exceptionally accurate in order to hit small targets, lightly constructed to provide explosive expansion while minimizing ricochets, and lightweight to obtain high velocities with flat trajectories. The extremely flat shooting varmint round is perfect for taking small game at unknown distances. Competitive shooters on the other hand tend to favor longer and heavier bullets with an aerodynamic boat tail design. These long bullets have a superior ballistic coefficient which allows them to maintain a high velocity for a longer distance, thus making them less prone to wind drift at extended ranges.

One concern when loading heavier longer bullets for your AR is the overall cartridge length. Heavier bullets are longer, and there is a limit to how far back they can be seated. Standard AR-15 magazines can hold cartridges up to 2.275 inches long. If you are loading rounds with heavy 79 grain or heavier bullets, such as 90 grain Sierra MatchKings favored by long range target shooters, the overall cartridge length will likely exceed 2.275 inches, requiring you to load and fire these handloads one at a time. If you are preparing a load that is over-length, it is important to make sure that your barrel is designed to handle it. A barrel with a 1:7 twist is generally not sufficient to stabilize bullets weighing over 77 grains (however some shooters claim to be able to stabilize 90 grain bullets in a 1:7 barrel), but more importantly, in longer handloaded cartridges the bullet could be swaged up against the lands of the rifling and cause overpressure in the case. Barrels for the longest of these loads will usually be custom made with a 1:6 or 1:6.5 twist rate and have a longer leade (the unrifled portion of the bore just past the chamber) to fit the longer bullet.

Depending on the weight of the bullet you are pushing, you will need different powders. Faster burning powders are more effective for propelling relatively light weight bullets. Slower burning powders in general should be used with heavier bullets. For our purposes here, powders such as Reloader 7, Reloader 10X, Accurate 2015, IMR4198 or Hodgdon H322 are excellent choices for accurate varmint loads topped with light 40 grain to 55 grain bullets. Reloader 15, H4895, IMR4064 or Varget are all good choices used for accurate match loads that propel heavier bullets weighing 60 grains and more.

When developing a load, always start at 75% of the manual recommended max load and work your way up, checking for signs of overpressure as you gradually increase the powder charge. If you don't have enough powder of one type or another, get more: never mix powders! Mixing powders can result in unpredictable burn rates and could cause a case rupture or detonation.

When choosing a primer for your match loads, stay away from hard military style primers. Most match triggers will not generate primer strikes hard enough to reliably shoot hard primers. Instead, stick with high quality standard small rifle primers such as CCI 400 or Winchester WSR primers for most loads, and Federal Gold Medal 205M for heavier match loads using slower powders.

Brass for match grade or varmint loads should always be cleaned and polished. This not only makes it chamber better, but it removes any carbon or debris from the case resulting in better more consistent powder burn. When resizing, don't rely on just a neck resize. For the most accurate loads your brass should be fully resized to ensure a consistent case capacity. Fully resized cases also fit the chamber better. What brand of brass you use isn't particularly important, but some shooters prefer Winchester or .223 Remington brass due to the consistent case weight and wall thickness.

When trying to wring every bit of accuracy from a handload, the devil is in the details. Turning the neck of your brass will help to ensure that your case mouth is perfectly round and concentric with the case body, giving you a consistent crimp and seal all the way around your bullet and positioning it perfectly concentric with the bore. RCBS makes a case neck turner and .223 pilot to help you turn the perfect case neck. Necks that are out-of-round can have gas escape around the bullet prior to the bullet entering the bore and result in an uneven bullet release. A perfectly even bullet release helps to ensure that it swages onto the rifling evenly.

Handloading Procedure
One of the primary reasons for handloading is that it gives you the ability to ensure absolute consistency among all of the rounds. Handloads that are quickly and carelessly assembled may be great for plinking and making a bunch of noise, but they are useless for precision shooting. Additionally, carelessly assembling your rounds can be dangerous! Double charged or poorly measured loads can destroy your expensive rifle and kill or seriously injure you. When sitting down to reload, get rid of all possible distractions. Never watch TV or have a conversation while reloading. Dividing your attention between the task at hand and something else can result in a mistake that could prove deadly. Remember that the more attention you give to the quality and consistency of your loads, the more accurate they will be.

See our article on reloading necked rifle ammunition for more details on the reloading process.

Example Loads

BulletBullet WeightPowderPrimerOverall LengthCharge (grains)Velocity (FPS)
Hornady V-Max35 grAccurate 5744CCI 4002.1321.13602
Speer SP40 grReloder 7CCI 4002.0620.53011
Speer SP40 grReloder 10XCCI 4002.0624.53481
Nosler BT40 grAccurate 2015CCI 4002.26025.43671
Speer SP45 grReloder 7CCI 4002.155203059
Speer SP45 grReloder 10XCCI 4002.155243292
Nosler BT50 grReloder 10XWSR2.224.23389
Nosler BT50 grReloder 15WSR2.2283356
Speer HP52 grReloder 7CCI 4002.220.52931
Speer HP52 grReloder 10XCCI 4002.222.53179
Nosler BT55 grAccurate 2015CCI 4002.23024.03215
Speer SP55 grReloder 10XCCI 4002.175233159
Hornady V-Max55 grVargetWSR2.24027.03344
Speer FMJ62 grReloder 15CCI 4002.25525.02832
Sierra HPBT69 grReloder 15Fed 205M2.2625.52956
Hornady A-Max75 grH4895Fed 205M2.27324.52861
Swift Scirocco75 grVargetFed 205M2.27023.02714
Sierra HPBT77 grReloder 15Fed 205M2.2624.12783
Sierra MatchKing90 grH4895Fed 205M2.55021.72600
Sierra MatchKing90 grIMR-4064Fed 205M2.55022.42600

All load data presented here should be used with caution. Consult a reloading manual and always begin with a reduced load to ensure that they are safe in your particular rifle before proceeding to full power loads. Cheaper Than Dirt! has no control over the quality of the components that you choose, the condition of your rifle, or the actual loadings you use, and therefore assumes no responsibility for your use of data presented here.

Wednesday, May 19, 2010

Extreme Heat Survival

Summer is upon us, and with it comes fun in the sun and time spent playing at the beach, in the woods, or at your local sports field. But with the summertime sun comes the dangers of exposure to extreme heat.

Survival in extreme heat is a skill that everyone should have. It doesn’t take much for anyone from all walks of life to suddenly find themselves in a dire situation. You don’t need to be stranded in the desert or lost in a steamy jungle to be subject to the threat of high temperatures. Whether you find yourself stranded on a sun-baked highway or stuck in a heat wave, this guide will help you survive the extreme heat.

Extreme Heat Is Deadly
Heat waves have some of the highest mortality rates of all weather phenomenon. The CDC reports that between 1979 and 1999 there were 8,015 heat-related deaths in the United States alone. When severe weather strikes it often leaves thousands or even millions without the power to run an air conditioning or fans. In 1995 a heat wave killed approximately 600 people in Chicago in only 5 days. As recently as 2003 a heat wave in Europe killed more than 52,000 people. In the aftermath of Hurricane Katrina many people who survived the hurricane succumbed to the suffocating heat and humidity.

Image courtesy of Paulo Otávio, licensed under Creative Commons.

One of the leading causes of death in both the Chicago and European heat wave was poor air circulation and a lack of air conditioning. Some residents in Chicago decided not to open their windows at night for fear of crime. Other residents decided not to run fans or air conditioning due to the increased cost of power consumption. These decisions ultimately and unfortunately led to death in some cases.

There are three things you must consider when you need to survive in an extremely hot environment: water, shade, and activity level. Failure to take any one of these things into account can result in a dire situation very quickly.

Planning Activity Levels
Development of a buddy system is crucial to make sure that the elderly and infirm are taken care of in a heat wave. Buddy systems are also a good way to keep yourself safe. Often the victim of heat illness does not realize that they are succumbing to the heat because of the effect that heat has on the brain. With a buddy, you can keep an eye on them, and they on you, so that you have a second set of eyes watching for possible symptoms of heat stress. Prior to being in an extreme heat situation you should have a plan on what to do when faced with the problems that severe heat brings. Begin by taking an inventory of the tools, equipment, and materials that you have access to. Address the need for shade and water first, then focus on ways to establish an airflow or other cooling system. Include in your plan a schedule on when to engage in any physical activity at times when any heat will have a minimal impact.

Plan to have outdoor activity curtailed, and indoor activity limited to areas that can be kept cool. All activity you do raises your body temperature. The more vigorous the activity, the faster and higher your temperature goes and the more your body must work to keep you cool. If you must engage in outdoor activity in the heat, try to limit your work to the early morning hours when it is the coolest. While walking or working in the heat, breathe through your nose and keep conversation to a minimum to reduce moisture loss through respiration.

One of the best defenses to high heat is hydration. The human body requires water to function, and sweating in high heat depletes that water supply. In extreme heat, it is possible to lose as much of 2.5 liters of sweat per hour. All of that water and electrolytes must be replaced, so hydration is key. It is much more difficult for your body to stay cool if you are dehydrated. Hydration is not only necessary for sweat, but it also helps regulate body temperature by making it more difficult for the body to heat up rapidly. Heating up a liter of water just one degree requires almost 4000 BTUs (British Thermal Units). If your body is missing those 2.5 liters of water it is that much easier for the heat to raise your body temperature, and your body will need to sweat that much more to keep you cool.

Drink water whenever you are thirsty. Going without water in an attempt to conserve supplies may seem like a good idea, but because of water’s importance in maintaining body temperature you should always drink when thirsty to maintain hydration. If you find yourself running low on water, seek other sources, but under no circumstances should you ration water in an extremely hot environment. The risk of overheating increases exponentially as you become dehydrated. Hydration backpacks are a convenient way to carry around as much as 3 liters of water.

As important as proper hydration is the maintenance of a proper electrolyte balance. Hyponatremia is a condition that can lead to coma or death, and is caused by sodium levels in blood plasma that are too low. Symptoms can include nausea, vomiting, and headache, although most victims exhibit no symptoms whatsoever before dropping into a coma. Hyponatremia can occur through the loss of electrolytes through sweat, or through the over consumption of water (water intoxication). If you are sweating profusely and not replenishing the lost electrolytes, you can become affected by Hyponatremia. For this reason, when in an extremely hot environment, always remember to replenish electrolytes when you rehydrate. A teaspoon of salt per quart of water is all you need to maintain the right balance of sodium in your blood plasma. A healthy adult can process up to 15 liters of water per day. When hydrating, the important thing to remember is that liquids should be consumed over a period of time, not consumed all at once. To prevent Hyponatremia from excess water consumption, make sure that you consume no more than a half liter of water every 15 minutes.

Plan to have at least one gallon of water per person per day for drinking, but don’t neglect the cooling properties of water. Pools, cold showers or baths, or even lakes and streams are important resources to take advantage of in the heat.

Shade and Shelter
Shade or shelter is extremely important to protect you from radiant heat from the sun. Even if the air temperature isn’t that high, intense solar radiation can actually heat your body up to a much higher temperature. Because of this, shade is key to keeping cool. When considering the construction of a shelter in an emergency situation, try to keep your shelter elevated at least 12″ above the ground. The sun’s rays can heat up the ground as much as 30 degrees hotter than the ambient air temperature. Even resting in the shade on a stool or branch will keep you much cooler than sitting on the ground. If you must be exposed to direct sunlight, wear a light-colored, wide-brimmed hat or use a scarf and a loose fitting long-sleeved, light-colored shirt and pants. If the heat is still too much, try soaking your scarf or hat in water. The water will cool your skin and evaporate the same as sweat will. By keeping your skin temperature below 92 degrees you will minimize sweating and the moisture loss associated with it.

Air conditioning is the easiest way to stay cool in the heat, but if you do not have air conditioning, you will need to take other measures to stay cool. Consider going to public areas with air conditioning if they are available. During heat emergencies, most municipalities make public facilities such as libraries, community centers, or sporting arenas available for the public to use as a refuge from the heat.

Even if air conditioning is not available, it’s important to have air flow from fans or some other source. Air circulation is vital in helping the body to stay cool. When your body becomes over heated it opens up capillaries near the surface of the skin and sends a message to sweat glands, signaling them to release sweat. The sweat evaporates into the air, and the evaporative cooling effect then reduces the temperature of the skin as well as the blood in capillaries near the skin. That cooler blood is circulated throughout the body to maintain proper body temperature. Without air circulation however, the sweat is not able to evaporate as easily. Stagnant air makes evaporative cooling from sweat less efficient. While you do not want high wind, some airflow is necessary to maximize the cooling efficiency of sweat. A high wind in a hot environment acts as a convective oven, increasing the heating effect on you while at the same time increasing dehydration.

If you are indoors and have electricity but no air conditioning, keep windows closed in the morning and utilize fans for airflow. The radiant heat from the sun rapidly heats up the air outdoors, but the building’s insulation will keep it cooler than the outside air. As the day heats up, it will become necessary to open windows to move hot stagnant air out of the building and allow breezes to cool the indoors. By opening windows on the windward side of the structure as well as the leeward, you can create a cross flow of air through the building.

If you have the equipment, you can set up an evaporative cooling system. With electrical power, swamp coolers (also known as evaporative coolers) or fan-powered misting systems can be utilized to cool the air. These systems work best in low humidity environments where a fine mist is sprayed into an airstream. The tiny water droplets quickly evaporate into the air, causing a 15-20 degree drop in temperature. Swamp coolers are similar and use materials soaked in water over which air is blown. Again, the water in the material evaporates into the air, causing a 15-20 degree drop in air temperature from the evaporative cooling. Even without a powered fan, misting systems can still be incredibly effective at reducing the surrounding air temperature. These systems are available commercially, but they can also be easily constructed by a qualified individual from a fan and some plumbing parts. Always exercise caution when working around water and electricity.

Surviving Extreme Heat
A variety of tactics and techniques can be used to combat heat stress both in an urban and in a survival environment. If you have a plan for the situation you will find yourself at an enormous advantage and better able to beat the heat. By staying cool and hydrated in the shade and planning your activities around the hottest parts of the day you will be able to endure even the worst heat that mother nature can muster

Tuesday, May 18, 2010

To Chrome or not to Chrome? Myths and Facts of Chrome-Lined Barrels

Ever since the military began chrome-lining barrels on standard issue machine guns and rifles there has been debate concerning the benefits and disadvantages of chrome-lined barrels. Many of the benefits of chrome-lining are shrouded in myths and misconceptions. Chrome-lining protects the barrel from corrosion, but this is not the main purpose for lining a barrel. Chrome-lined barrels are also easier to clean, but the military would not invest in a chrome-lined barrel just to save a grunt some time swabbing out the bore.

Years ago, with the introduction of high powered machine guns and semiautomatic rifles capable of sustained high rates of fire, military armorers began to notice significantly increased barrel wear and erosion. Older models of the most powerful machine guns were capable of “shooting out” a barrel in less than 1,000 rounds! Chrome-lining was introduced to increase the barrel life, allowing more rounds to be sent down range in less time without the need to replace the rifle barrel.

Muzzle flash from an AR-15 rifle, demonstrating the immensely hot gases generated by powder combustion. Photo courtesy of bdjsb7 licensed underCreative Commons.

Nowadays, almost all military rifles are universally chrome-lined to protect the rifle barrel from excess erosion. AR-15 rifles are particularly prone to erosion when fired rapidly, in part due to the high velocity of the round, and in part due to the high pressures generated by the cartridge. While it’s not uncommon for military rifles to experience high rates of sustained fire, it’s also not difficult to fire a semiautomatic AR-15 at rates exceeding 100 RPM. Under sustained fully automatic gunfire, or rapid semiautomatic fire, an enormous amount of heat is generated. That heat is what can quickly ruin a barrel.

The leade (the unrifled portion of the barrel just forward of the chamber), as well as the first few inches of rifling, is subject to temperatures hotter than the surface of the sun and pressures exceeding 50,000 PSI. Under slow fire conditions this area is able to cool a sufficient amount in between strings of fire. Under sustained rapid fire however, there is no time for the heat to dissipate and temperatures soar into the thousands of degrees Fahrenheit. This can quickly cause damage by eating away at the rifling, “burning up the barrel” with the combination of extremely high heat and pressure. Hard chrome-lining the bore protects the leade and rifling with a thin coat of heat and pressure resistant chrome. This greatly prolongs barrel life in rifles that are fired for prolonged periods in full-auto or rapid fire semiautomatic modes by preventing damage to the leade and rifling.

There are many people who argue that chrome lined barrels are less accurate than an otherwise identical steel barrel. All things being equal, this is true, but for most shooters, the degree to which accuracy is lost by using a chrome-lined barrel is generally unnoticeable. A chrome-lining does diminish the sharpness of the rifling, but the accuracy loss from this is not insurmountable. Consider the Fabrique Nationale SPR rifle (what is essentially a gussied-up chrome lined Winchester Model 70) is capable of shooting a 1/2 MOA group at ranges up to 800 yards away. A sub MOA gun is a fine rifle by nearly anyone’s standards, and most well built chrome-lined AR rifles are capable of 1/2 MOA groups as well.

So, when should you go chrome lined? Most casual shooters will get by just fine with either chrome-lined or non chrome-lined barrels. The fact is, most of us don’t get out to the range often enough, nor engage in rapid fire when we do (most ranges prohibit the practice). Even shooters who occasionally engage in periodic rapid-fire with their AR-15 style rifle may not notice the effects of excess barrel wear for a number of years. A good non chrome-lined barrel can last for over 5,000 rounds before it begins to show a loss of accuracy. If you shoot 1,000 rounds a year, even blasting through a full magazine as fast as you can pull the trigger on ever range trip, it could take 5 years or more before any significant loss of accuracy begins to become apparent.

When deciding whether to get a chrome-lined barrel your budget may be the deciding factor. Non chrome-lined barrels are significantly less expensive than a similar chrome-lined barrel. For a shooter who wants to build a quality AR-15 with less initial investment, non chrome-lined barrels represent a great cost-saving measure, combining the inherent accuracy of a stainless steel or chrome-moly steel barrel with an acceptable barrel life for a hunting or sporting arm. The up front savings can easily outweigh the cost of rebarreling your AR years in the future.

For the serious shooter who needs maximum barrel life as well as accuracy, a chrome-lined barrel represents the best of both worlds. The accuracy lost from a chrome lining amounts to less than 1/4″ at 100 yards, a negligible amount for most AR rifles used in tactical applications. If you do decide to go with a barrel that is not chrome-lined, be aware that you can significantly reduce the barrel life by quickly dumping 3 or 4 magazines through it without stopping to let it cool down.

If you’re building a match rifle that will be used solely for competitions where you’ll be firing slowly and you need a great deal of precision, stick with a chrome-moly or stainless steel match grade non chrome-lined barrel. If you think you’ll ever want to use your AR-15 for tactical applications, or even just rapid-fire plinking, drop the extra cash and get a chrome-lined barrel. Otherwise, be aware that without a chrome-lined barrel your AR-15 should be allowed to cool between magazines in order to avoid damaging the barrel.

Friday, May 14, 2010

John Moses Browning and His Creations

John Browning was the most prolific firearms designer in the United States and perhaps the world. He lived in a time when the firearm was coming into the modern age, and his impact on the principles of firearm design helped to shape the growth of the modern firearm industry. In fact many people feel that Browning WAS the basis for the modern age of firearms! Some of his designs would be used for 100 years and many are still in use today.

John Browning was more interested in creating his designs than the manufacturing business, and he sold his designs off to dedicated firearms manufacturing firms. Thus, some of his designs do not bear his name, but they bear his indelible style. A Remington Model 11 is a Browning Auto-5 by any other name; the same shotgun but with a different manufacturer.

Early Life

John was born in 1855; one of his Mormon father’s 22 children. While working in his father’s gun shop in Ogden, UT he began to create his own designs and show promise in building firearms at the early age of 14. After his father’s death in 1879, he and four other brothers formed a new gun shop and quickly had so much work that they could not keep up with demand due to lack of capital for equipment. John was frustrated because the hard work at the shop gave him no time to develop new designs.

One day, a salesman from Winchester firearms bought one of John’s single-shot rifles and sent it to the home office. The general manager quickly negotiated for the manufacturing rights which Browning quickly sold for $8,000, using the capital set up his own shop for design work rather than a factory. This began a long term association between Browning and  Winchester which lasted until he had a licensing disagreement with them and left for Belgium. From 1883 until 1902, John designed many firearms for the Winchester Company. Five of these designs became best sellers.

Unfortunately for Winchester, they made a poor decision in refusing to go along with Browning’s manufacturing license-royalty stipulations for one of the all time great shotgun designs, the Auto 5. Browning simply packed up his goods and went to Belgium where he designed for Fabrique Nationale Herstal located in Liege, Belguim, thus ending his long and productive partnership with Winchester.

1911 Colt

Probably the most widely known and recognized of Browning’s firearms is the Model 1911 Colt. The 1911 is undoubtedly the most copied firearm design ever. It is interesting to note that is not called the 1911 Browning. He was working for Colt at the time and they bought the rights to his new design. The name 1911 was for the year it was introduced for manufacturing. Browning had some prototypes named the 1903 and 1908 that were the basis of the 1911. Of course, he had designed other successful pistols for Colt while he was there such as the famous Colt 1903 .380 Pocket Model and Colt Woodsman .22 Long Rifle automatic pistols.

Virtually every firearms manufacturer today has at least one version of the 1911 in their lineup, and most have quite a number of varieties. This historic pistol has fought in just about every war since it was introduced in 1911 and is still in use with the US military in some specialty areas. It is carried by police, bodyguards, and private citizens for both offensive and defensive use and can be found in a variety of calibers apart from the original .45 ACP.

The most amazing thing about the 1911 is how perfect it was from the beginning of production. Nothing really required a change, but it got a few comments for improvement after WWI and by 1926 they were incorporated as mentioned later. These changes were hardly worth making for the most part. In fact, some still prefer the flat mainspring housing and the original design in general.

However perfect the design was, it still underwent some changes in between the drawing board that resulted in the 1911 design we have all come to love.

In 1906, the US Army announced it was looking for a new handgun and caliber to replace the .38 revolver that had been in use for years. John Browning, working for Colt at that time, already had a semiautomatic model in development that he entered in the trials. It fired a new caliber round he had developed that was similar to the .38 Super Automatic, but changed it to accommodate the cartridge the Army wanted, the .45 Automatic Colt Pistol (ACP). During the initial selection process, eight models were assessed.

By 1907, the Browning-Colt entry was selected along with the Savage entry for further evaluation. Colt engineers worked with Browning to perfect his entry in the testing, making sure every part was made in the best possible manner. In the trials, Browning’s pistol was fired 6000 rounds with cleanings and cooling periods every 100 rounds in that test phase, then fired with various deformed rounds, rusted in acid, dipped in mud and sand, and went through even more torture tests. It came through with flying colors as it never misfired or broke a part. In fact, the competitor’s entry was practically destroyed in the same process. The final analysis of Browning’s entry is as follows:

“Of the two pistols, the board was of the opinion that the Colt is superior, because it is more reliable, more enduring, more easily disassembled when there are broken parts to be replaced, and more accurate.”

During the trial process, several changes were made to the initial design including changing to a single swinging link, an improved manual safety, adding a grip safety, and a slide stop. The other significant change was to the grip area of the frame, which was angled more acutely and slightly longer than Browning’s first design. These improvements totally changed the appearance of the original design from one resembling the Colt Pocket Model on steroids to the venerable 1911 we know today. On March 29, 1911, the Colt pistol was selected as the official sidearm of the US Armed Forces. Thus, the name of the pistol became the “Model of 1911 US Army.”

For WWI, production of the Colt 1911 ran as high as 1,000 units in May, 1918, to 2,200 units PER DAY in the summer of 1918! This is the total of both Colt and Springfield Armory which helped ease the wartime production crunch.

Total 1911’s made by the end of 1918 was 602,153 complete units.

A short list of improvements were made after WWI starting in June, 1926. At that time, the 1911 was designated the 1911A1. Changes were as follows:

  • Arched and checkered mainspring housing

  • Longer grip-safety spur

  • Relief cuts around the trigger housing

  • Shorter trigger with knurled face

  • Wider front and rear sights

By WWII, John Browning had already passed on. However, his design would grow to even greater fame in that conflict. A number of manufacturing contracts were let to support the wartime demand. These contractors were Singer Sewing Machine, Remington Rand, Union Switch and Signal, Ithaca, and of course Colt firearms. WWII production of the 1911A1 was about 2.5 million units.

The 1911 was made under contract outside the country in places like Norway and Argentina, and as knock-offs in countries all around the world. Many different variations on the basic government model were released, such as the National Match (later the Gold Cup), Combat Commander, and too many others to list. Since the patents have expired on the design, just about any manufacturer can produce their version of the 1911 pistol.

John Browning would be very pleased and proud of his design, as the Model 1911 has been in use almost 100 years. It is virtually a tour-de-force in the handgun world and will never be matched by any other pistol in its history making achievements. This is not the obituary for the 1911 either. For many years to come tt will continue on in the civilian world as one of the most popular models to buy for sport, competition, and self-defense use.

Browning Auto 5 Shotgun

Another of John Browning’s great designs is the Auto 5 auto-loading shotgun. It is perhaps one of the strongest, most durable semi-automatic shotgun designs ever made. Produced for almost 100 years, it was the first mass-produced semi-automatic shotgun and the second best selling semi-automatic shotgun in the US after the Remington 1100. John Browning considered it his best achievement. First designed in 1888 and patented in 1900, it revolutionized the shotgun world. It is estimated that over three million copies of the Auto 5 have been made worldwide. Noted nickname of the Auto 5 is “Humpback” due to the squared-off rear end of the receiver.

This is the firearm that caused the split between long-time partners (19 years) Winchester and Browning. Winchester refused his terms for licensed production and royalties and he took his design elsewhere. Browning went to Remington next, but while he was waiting in the office for his appointment, Remington's president had a heart attack. (Remington would later produce the Auto 5 under another designation, the Model 11, when tariffs made it unfeasible to import from FN). One month later, he then took it to Fabrique Nationale Herstal in Liege, Belgium where they gladly accepted the offer. This put the struggling FN Company on the map and the rest is history, as the saying goes. Except for a break during the WWII Nazi invasion, FN produced the Auto 5 for Browning continuously until 1977.

In 1977, The Browning Company chose to move production of the Auto 5 to Miroku, Japan where production continued until the model was discontinued in 1999. High cost of production is generally given as the reason for dropping the Auto 5.

The interesting feature of this design is that the barrel recoils back with each round fired, thus cycling the bolt to recock, eject, and load shells on each stroke. This is referred to as a long-recoil action and was the first of its type. The receiver also features a magazine cut-off lever to permit single shot operation, if desired, even with a fully loaded magazine tube. The amount of recoil is controlled by a set of friction rings that can be situated to provide more or less recoil, depending on the shooter’s needs and desires. The friction ring concept was one of the small, but important details that led to the initial success of the Auto 5 since it served to smooth-out the rather unreliable charge level of early smokeless powder shot-shells.

Over the years, 12, 16, and 20 gauge and many special versions have been produced. Browning introduced the “Final Tribute” version in 1999 as the last model under regular production. The 20 gauge Auto 5 is still available from the Browning Custom Shop.

It is interesting to note that Browning himself bought the first 10,000 Auto 5’s off the FN line to sell in the US market. He sold all of them within only 12 months.

Winchester 1894 Lever-Action Rifle

This is another all time classic rifle in use for over 100 years and probably has been used to bag and tag more deer in the US than any other firearm. The Winchester 1894 lever-action rifle was designed by Browning when he was on good terms with Winchester. Winchester sold this model until they stopped producing firearms in 2006. It is most famous in the original caliber of .30 WCF (Winchester Center Fire). Oddly enough, Marlin renamed the round the .30-30 to avoid putting the Winchester name on a Marlin product. To their credit, the name caught on and .30-30 Winchester is how the round is referred to these days.

This lever-action rifle, also known by the name “Model 94,” was a gamble for Winchester because it was the first Winchester to chamber the “new-fangled” smokeless powder cartridge. This gamble paid off for the Winchester Company as it was a huge success. This was the first civilian sporting firearm to sell 1 million copies and has sold over seven million copies to date.

Browning M2 .50 Machine Gun

Known as the “Ma Deuce” or simply “Fifty Cal”, the M2 is perhaps the perfect heavy machine gun. It has served not only as a heavy gun on tanks, for infantry on M3 tripods, for defense and offense on boats and ships, but has been installed on countless aircraft from WWII to almost the present day. It is just another of the timeless Browning designs. Not only did John Browning develop the firearm, but the .50 Browning Machine Gun (BMG) round as well! It is hard to get a handle on the power of this cartridge, but it can be aimed and accurately delivered to targets at ranges of 0.5 to 1.5 miles. Quite impressive when you stop to let that sink in.

In 1918, 4-star General Pershing requested a heavy machinegun be made to be effective against aircraft, tanks, and armored cars. This request was passed down to Colt and then to John Browning. John basically enlarged the M1917 .30 caliber gun to accept the .50 caliber round. Browning also based the new cartridge on a scaled-up .30-06 round. Both concepts came together well as the .50 M2 machine gun is a potent combination of firearm and cartridge.

The new gun was first tagged the Model 1921 .50 caliber and was water-cooled and belt fed. This was the primary anti-aircraft gun for the Infantry and Navy. This design was modified further to accept air-cooled barrels which were found to be too light for sustained fire. This was designated the M2 Heavy Machine Gun. Later, the lighter barrels were replaced with a very heavy model and the gun retagged the M2HB (Heavy Barrel). In 1938, the barrel changed again, this time in length. The longer barrel M2HB provided increased range and energy and was fitted to just about every US aircraft in WWII, to the tune of just under 2 million copies between 1941 and 1945.

A great compliment was paid to the M2 by none other than Luftwaffe Field Marshal Herman Goring (warmly known to his enemies as “the fat man”), he said, “If the German Air Force had had the Browning .50-caliber, the Battle of Britain would have turned out differently.”

After WWII, the M2 continued to serve not only US forces, but was accepted in militaries around the world. It is still in wide use including in the US armed forces.

After almost 90 years of service, the U.S. Army has moved to replace the M2. Three prototypes of a lightweight .50-caliber machine gun have been produced by General Dynamics Armament and Technical Products and weighs about one-half of the current .50-caliber M2HB. According to General Dynamics, it fires with less recoil and greater accuracy than the M2. Even with this new development, the M2 will still be in service for several more years.

Browning Hi-Power Automatic Pistol

The Browning Hi-Power pistol was initially developed by Browning in 1922, but did not reach production until some years after his death. It is quite an attractive pistol and was perhaps the first pistol to utilize the double-stack magazine for high capacity in a fairly compact space. This was a staple of the FN Company for many years. It seems that Browning's designs put meat and potatoes on the table for FN like they did for Winchester.

The Hi-Power began as a request by the French military for FN to design them a new pistol with specific requirements; the caliber being 9mm and capacity being at least 10 rounds. FN, in turn, passed the design work to John Browning. John had a design that was successful in the 1911, but that was patented by Colt Firearms. Thus, he had to come up with another pistol design. Carefully working to avoid any 1911 designs, he laid out 2 basic models; one a blowback and the other a locking-breech recoil design. A new concept was the staggered-magazine design which allowed twice the capacity in little more space than a single-stack magazine. The locking breech recoil design was selected for further development. By 1934, the design had been finalized and was ready for production as the Browning P-35. Strangely enough, by this time France had gone with another firearm and backed out of the deal, but Belgium decided to go with the new Browning-FN design for its military in 1935.

While John Browning laid out the basic design and concept in 1922, it was up to FN designer Dieudonne’ Saive to complete the work on the Hi-Power. Saive became FN’s chief designer after Browning’s death and would later design the FN-49 and FAL rifles.

The Hi-Power derives its name from the high capacity magazine that holds 13 rounds. This was double the fire power of contemporary handguns at the time; quite an achievement.

It is interesting to note that the Hi-Power served on both sides of WWII combatants. It was also produced for the Nazi forces after the FN plant was taken captive in 1940. So, it is possible to add one to your collection that has the Nazi acceptance stamps and “dirty birds” if you are an avid collector.

Hi-Powers were also made in Canada by John Inglis and Company for Allied forces during WWII. It is still in service in a number of standard and covert or special ops military forces as well as police departments worldwide.

We can only assume that John Browning had too many other irons in the fire at the time to flesh-out this great pistol before he passed on.

Browning 1919 .30 Machine Gun

The Model 1919 medium machine gun is still in use by some countries around the world. It was originally designed for the venerable .30-06 Springfield cartridge but over the years has been updated to the 7.62 NATO cartridge. It saw use for the US military in WWII, Korea, and Vietnam. Like its bigger brother, the .50 M2, it has been used in just about every configuration imaginable for infantry, fixed wing aircraft and choppers, tanks, boats, and more.

The 1919 is the air-cooled derivative of the Model 1917 water-cooled machine gun of WWI, also designed by Browning. The 1919M2 (not to be confused with the .50 M2) was the aircraft version and was considerably lighter and had a much faster rate of fire. Model 1919A4 was the most widespread version and saw use by infantry as well as it was mounted on Jeeps, tanks, and ships.

The 1919 served well, but was ultimately replaced in the late 50's and early 60's by the M60 machine gun, which was designed around the 7.62 NATO round.

Browning Automatic Rifle (BAR)

One of the longest used light machine guns for the Army is the BAR. It served from the end of WWI to the Vietnam War era and at least one Depression Era gangster chose it as his favorite sidearm. Clyde Barrow stole one from a National Guard Armory, cut it down for his special purposes and was always considered extremely dangerous to lawmen with this weapon in his hands. One of the lawmen that ambushed Bonnie and Clyde in Louisiana used a Colt Monitor to cut them down. The Monitor is a police version of the BAR.

The final version of the BAR came in 1939 and saw its greatest success from that time forward. It was somewhere in the middle zone for a light machine gun since it was a bit hard to hold down under full auto fire and had too small a magazine to keep intense fire on the enemy. However, like all Browning’s designs, it was always fully functional and reliable. Every Army squad in WWII had a BAR carrier. Due to its bulk and heft, (19 pounds), it was usually assigned to the largest man in the squad.

The BAR fired the .30-06 cartridge which was the basis for the US Military small arms for the first half of the 20th Century and carried over for another 25 years. The BAR was a real threat to German as well as Japanese troops as it could be quickly brought into play on any enemy position with its devastating high rate of fire.

The BAR served as the inspiration to create improved versions or perhaps “knock-off” light machine guns in several European countries after WWII.

Undoubtedly playing on the success of the military BAR, Browning Firearms Company used that name for a highly successful sporting rifle, the BAR. It is offered in several calibers and has enjoyed the same great reputation of its military namesake. Gas operation and fair heft serve to make the sporting BAR a nice mount for larger magnum calibers because it takes the “sting” out of the .300 and .338 Winchester Magnums.

Browning Superposed Shotgun

This is the last design John M Browning was working on when he died at the FN factory in Liege, Belgium. He was in Val Browning’s office, probably discussing the still-undecided single-trigger system for the Superposed, when he died of a heart attack at age 71. Val Browning worked to finalize his father’s design and the Superposed went into production in 1931 with a double trigger. Val continued to work on a single trigger and selector which his father wanted to see in the shotgun. In 1939, these improvements were introduced. Production was stopped during the Nazi invasion of WWII in 1940 and resumed postwar in 1948. The Superposed continued to be produced through the years and underwent various changes and improvements. 1976 was the last year for the Superposed to be produced for Browning Firearms due to very high production costs, but FN continued to produce it for the European market.

A very similar over-under design, the Citori, was introduced by Browning and produced by Miroku Firearms, Japan, in 1973 and continues in the Browning line today. The Citori is a lighter, scaled-down, less-expensive-to-produce model of the Superposed.

For the very deep pockets out there, Browning still offers the Superposed through the Custom Shop under the model name B25.

The Superposed shotgun, also known as the over-under shotgun, was an innovation in the shotgun world and it was Browning’s aim to make it cheap enough for the common man to own. His design is still a favorite today. Previously, only the landowning gentry could afford such a grand design. John Browning’s design was something of a boat-anchor, but it certainly took any punishment handed out in the field. Superposed guns will probably last many life times and are true family treasures to be passed down for generations.

Browning's Legacy

Many firearm historians will argue that John Moses Browning was, and still is to this day, the world’s greatest firearms designer. The firearms described here are just a few of his works of genius. Much more can be learned about Browning and his other designs both in the many publications available and countless online sites. Take the time to study Browning, as it is likely that you own, have owned, or will own a firearm based off of his timeless designs.

Thursday, May 13, 2010

Barrel Twist in the AR-15

Since the early days of firearm building, armorers noted that if they imparted spin to the projectile that it greatly enhanced in-flight stability and accuracy. The earliest rifles had numerous bands of metal that were forged together and twisted to create the helical shape of the rifle groves. As machining processes were developed and refined, hammer forged barrels became popular as they were much stronger and much more precise.

Rifle twist is represented with a 1 a colon and another number, such as 1:7, 1:9, 1:10, 1:12, etc. The second number is the length in inches that it takes for the grooves to make one complete revolution. Thus, a 1:10 twist rifle barrel makes a complete 360 degree revolution in 10 inches. A 1:7 rifle barrel on the other hand makes a complete turn in only 7 inches, giving it a much tighter faster rate of twist (and consequently a greater RPM to the bullet).

The Greenhill Formula, developed by Sir Alfred George Greenhill, lays out the mathematics for computing the optimum spin and rifle twist necessary to stabilize a bullet. His most basic calculation is

where C = 150 (or 180 for muzzle velocities greater than 2,800 fps) D = bullet caliber (in inches) L = bullet length (in inches) and SG = bullet's specific gravity (10.9 for most lead bullets). For lead core bullets, the second half of the equation is disregarded as the value of the square root of 10.9/10.9 is 1, however the value will need to be calculated for steel core, steel jacketed, or frangible bullets as their specific gravity will vary. Because of the high muzzle velocity of most 5.56/.223 rounds, C should be set to equal 180 in the above formula.

What does all of this mean? For most shooters, not much. We're not going to delve any deeper into the mathematics of calculating the optimal barrel twist for various bullet designs. Instead, we'll lay out the basics and give you some good guidelines to go by when figuring whether or not your AR-15 barrel will stabilize a given round.

In general, you want a faster twist (lower second number) for a heavier bullets. Firing lighter bullets through a fast twist barrel can over spin them, causing inaccuracy from overstability and/or spin induced drift. Overstability occurs primarily in light weight projectiles fired from a fast twist AR barrel and causes the bullet nose to remain at a high angle of attack throughout the flight trajectory due to extreme gyroscopic stability. Extremely light weight thin jacketed varmint rounds that are overspun past 300,000 RPM can even fly apart from the immense centrifugal forces imparted by the bullet spin.

For 5.56/.223 bullets weighing between 35 and 50 grains you can use a 1:12 or 1:14 twist. 1:9 (probably the most common twist found in AR rifles) and 1:10 are good moderate twist rates capable of stabilizing bullets weighing from 45 on up to 69 and even 70 grain bullets. For the heaviest 5.56/.223 bullets you will need a 1:7 to 1:8 twist barrel in order to reliably stabilize bullets weighting between 69 and 90 grains.

There are some odd barrels out there being used to fire heavily customized .223 loads. Some custom barrels are available in a 1:6.5 twist and are capable of stabilizing 100 grain bullets, though that weight is not very common and difficult if not impossible to find. Extremely high velocity loads firing a bullet weighing 55 grains or less at speeds exceeding 4,000 feet per second require a very slow twist rate of 1:15 to 1:16.

Most shooters find that a 1:9 twist barrel meets their needs quite well, but if you're going to be firing heavier match loads or lighter faster varmint rounds you'll need to search for a barrel with a more appropriate twist rate.