The Rifle That Tracks Like An Artillery Cannon

Image courtesy of Big Horn Armory.

If you enjoy shooting your guns (and I’m assuming that you do since you’re on this site), then you know that, sometimes, you just want to shoot something with some serious power. Maybe you are a big game hunter and need something to take down that big animal. Or maybe your motivation is just because it can be done.

Whatever your reason, Big Horn Armory has put out a rifle that might catch your attention. They call it the AR500, and, while built on an AR 308 platform, it shoots rimless 500 S&W Magnum ammunition which they call 500 Auto Max. As Big Horn Armory says on their website, it is “[t]ruck stopping power in a platform weighing less than 10 pounds.” Tom Marshall describes shooting the rifle this way:

The rifle itself is built on an AR-10 receiver set. The .500 Auto Max round can be stuffed into an AR-15 magazine, and the AR500’s magwell is shortened to AR-15 length to accommodate the shorter mags. But building on an AR-10 base platform allows the use of heavier buffers and stiffer springs to mitigate the not-insignificant recoil. Specifically, Big Horn Armory uses an 18-pound recoil spring and a 3.8-ounce buffer. This, combined with a mid-length gas system and an “in-line” muzzle brake makes the AR500 … manageable. Felt recoil is still rather stout, maybe on par with shooting 3-inch magnum shells out of a 12-gauge pump gun, but not joint-busting.

The whole gun seems to track like an artillery piece, with a slow arcing movement to the rear with each trigger press. But the weight of the gun does bring it back down to level as part of its natural path of travel. The handguard is modular, but not to M-LOK or KeyMod standards. It uses an older-style system of screw-in short rail sections. While not quite as convenient as the current iterations of plug-and-play handguards, it does allow for user configuration. Our test gun shipped with a single 20-round AR magazine modified to accept five of the larger .500 cartridges. On that note, it’d be interesting to see how many could squeeze into a 30- or 40-round AR mag.

When it comes down to it, this is a rifle built for power, and Marshall indicated that the accuracy is good on this rifle. He does warn, however, that rapid firing will cause you to loose accuracy because of the amount of kick when shooting with it.


So, if you’re wanting something with some major stopping power in your arsenal, then you may want to take a look at an AR500. It may fit the bill for you.



  1. They are coming out with some really interesting calibers for the AR platform these days. This sounds like a monster at close range for sure! I would have to see some real world testing to pass judgement on it for real world long range use. That category is already pretty full and covered by some amazing calibers and weapons.

    • Keith C. Haas – In my view, the advantage of the .500 Automax is the sectional density of the fifty caliber slug has superior penetration as compared to the 12ga. 1oz. slug from a 3″ magnum.

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