The team at Big Horn Armory, known for its large-caliber lever guns like the Model 89, stepped into the AR world for the first time with the launch of the world's most-powerful AR-style rifle: the Big Horn Armory AR500 chambered in 500 Auto Max. The new platform, purpose-built for big-game hunting, also provides civilians, law-enforcement and military professionals with an incredibly powerful, threat-stopping platform that can be employed for checkpoint use and breaching applications.
“All we do at Big Horn Armory is design and make big-bore guns,” said Greg Buchel, president of Big Horn Armory. “Using the 500 S&W Mag. cartridge as our springboard, we wanted to bring back the concept of hunting using big-bore cartridges for the simple reason it puts game down immediately, regardless of the bullet’s construction or speed. As hunters ourselves, our goal is to bring game down efficiently and ethically."
Built on a DPMS-style .308 receiver, machined from 7075 aluminum, the AR500 features a gas-operated, semi-automatic action familiar to AR owners across the country and feeds from five-round magazines. The aluminum receiver features cuts on the front face of the magazine well as a textured gripping surface, and the area around the trigger guard is also recessed to offer a finger rest outside of the trigger guard when not firing. Additionally, all steel components used in the rifle are treated with a salt-bath nitride finish to guard against corrosion and wear.
Paired with the gun's receiver is an 18-inch barrel machined from stainless steel and finished with a 3/4x28 TPI threaded muzzle compatible with most aftermarket muzzle devices and sound suppressors designed for .50-caliber rifles. Each Big Horn Armory AR500 rifle ships with a flash suppressor. The barrel features a recessed crown and a twist rate of 1:24 inches. Internally and externally, the barrel is hardened to a Rockwell Hardness rating of Rc82 through a nitriding process that extends barrel life and protects it from the environment without altering the dimensions like other coatings.
To make the rifle the most-powerful production AR on the planet, the AR500 is chambered for the unique, straight-walled 500 Auto Max cartridge, a rimless version of the popular 500 S&W Mag. used in Smith & Wesson Model S&W500 X-Frame revolvers, the most-powerful production revolvers available to consumers. The cartridge can be loaded with any .500-inch diameter bullet weighing between 200 and 700 grains. The rifle is equipped with an adjustable gas block that allows the gas-operated action to be tuned for suppressor use with subsonic loads. Factory-loaded 500 Auto Max ammunition is available from Buffalo Bore and Underwood Ammo. Certain ammunition loads in this powerful big-bore cartridge can exceed 4,000 foot-pounds of muzzle energy when fired from the AR500. For comparison, a Winchester Super-X 2.75-inch 12-gauge shotgun slug, weighing 1 ounce, produces 2,488 foot-pounds of energy at the muzzle.
Other features found on the Big Horn Armory AR500 rifle include an Adaptive Tactical EX Performance M4-style collapsible stock constructed from high-impact polymer and outfitted with a generous, rubberized recoil pad. The rifle's fore-end is compatible with all M-Lok accessory attachments and features a full-length Picatinny rail running along the top edge of the handguard for the addition of optics and other devices. Integral sling-swivel mounts are located at the front and rear of the rifle. The total weight of the platform is 9.55 pounds, and the suggested retail price on the new gun is $1,999.