Friday, October 8, 2010

The AR-15 Platform As A Hunting Rifle

It’s hard to say where the trend started. Perhaps some Vietnam veteren in the deep south struggling with a feral hog invasion decided the best way to eliminate the varmints was the AR-15 he picked up after returning from the jungle. Maybe it was a rancher out in Midwest who liked the flat shooting 40 grain round for taking out coyotes. Wherever it began, it started a years long transition from traditional wooden stocked bolt action hunting rifles to the eventual production of Remington’s R-25 AR-platform rifle chambered in anything from .243 to .308 Winchester.

Now, before you dismiss the traditional 5.56mm/.223 caliber AR-15 rifle as a viable hunting weapon, lets go over some ballistics first. I know many will dismiss this rifle/caliber combination as a “poodle shooter” unsuitable for use in a war zone, much less as a hunting rifle for use on medium game, but let’s look at what the numbers say, starting with one of the most popular deer cartridges in the Unites States, the .30-30. Traditionally, the .30-30 used cast lead bullets with most weighing in around 160 grains. Though it was one of the first cartridges designed from the ground up to use smokeless powder, black powder was simply more available at the time and was commonly used when the .30-30 was introduced. Sitting atop a compressed load of FFF black powder the muzzle velocity of a 160 grain cast lead bullet was only around 1,600 feet per second, giving it a muzzle energy of just under 1,000 ft-lbs. While this performance pales in comparison to a modern smokeless powder propelled .30-30 bullet, it was more than adequate to take down what amounts to probably millions of deer over the decades. Moving on to the modern version of the .30-30 round we find that using smokeless powders a somewhat lighter 130 grain copper jacketed round nose flat point bullet is easily propelled to a muzzle velocity of 2,500 feet per second which results in a muzzle energy just a hair under 1,800 ft-lbs: much more than the older blackpowder version.

How does this traditional deer cartridge stack up against 5.56mm/.223 caliber ammunition? In fact, they are surprisingly similar. A standard 62 grain FMJBT round fired at 3,050 feet per second has a muzzle energy of 1,300 ft-lbs., more than our traditional 160 grain black powder propelled bullet but slightly less than a modern 130 grain smokeless propelled .30-06 bullet. Still, that gives the 5.56/.223 round more than enough energy to drop a good sized mule deer.

“But…” I hear you cry, “The .223 round has far too much penetration, it will just shoot through and through without doing much damage.”

Not quite. It’s true that the standard M855 round used by our military does have some overpenetration issues due to variations in the neck length, but heavier 69 and 75 grain hollow point or OTM bullets (both of which should easily by stabilized by most 1:9-1:7 twist barrels) have superb performance and fragmentation in less than 12 inches of ballistic gel. While ballistic gel is not a direct substitute for a deer, it does serve to give us a rough estimation of the round’s performance on a game animal. This evidence, when coupled with the thousands of anecdotes from wild boar and deer hunters who swear by the .223 AR-15 rifle/cartridge combination, should be more than enough to prove the viability of the .223 cartridge as medium game ammunition.

But, for those of you who still feel the need to step up to a larger caliber, there are plenty of AR-15 platform rifles out there chambered in calibers such as 6.8 SPC, 6.5 Creedmoor, .243 Winchester, .308 Winchester, and even 7mm-08. DPMS and Remington, both owned by parent company Freedom Group, have a line of rifles dedicated to these larger calibers. From DPMS we have the LR-308 platform and from Remington the R-15 and R-25 rifle, both dedicated hunting rifles available with a camouflage finish.

While the larger caliber AR rifles were initially dismissed by many traditional hunters as “overkill” or “not suitable for hunting” it didn’t take long for many to realize that there simply isn’t much difference between aRemington 750 or Browning BAR and an R-25 or LR-308 chambered in .308 Winchester. While some will undoubtedly prefer the traditional look of a walnut stock or the increased precision of a bolt action, it appears that the AR platform is here to stay as a viable option for small, medium, and with the .308 or 7mm-08 chambered R-25 large or dangerous game such as moose or bear.

The modularity of the AR platform makes it able to be quickly swapped over from an iron sighted .458 SOCOM brush gun to a scoped 6.8 SPC caliber rifle capable of much longer shots. No other rifle platform demonstrates such versatility. Combine this with the wide availability of aftermarket parts, and you can build an AR rifle to fill just about any role you can conceive of.

1 comment:

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