Wyoming-based Big Horn Armory recently put out a 308 AR-style rifle for big game hunters, big bore fans and law enforcement called the AR500.

The main feature to note on the AR500 is that it’s chambered in a new cartridge called the 500 Auto Max. Essentially a rimless version of the 500 S&W, the 500 Auto Max is capable of exceeding 4,000 FPE, the company claims. In addition, it can feed and fire from any .500 diameter bullet between 200 and 700 grains. You can get 500 Auto Max ammo from Buffalo Bore, Underwood Ammo and Midway USA.

“All we do at Big Horn Armory is design and make big bore guns,” Big Horn Armory president Greg Buchel said. “Using the 500 S&W magnum 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.”

Other features on the AR500 include a 1 in 24 twist, 18-inch stainless steel barrel surface hardened to Rc82 with Big Horn Armory’s nitride process. The barrel is threaded at ¾-inch x 28 TPI—standard for most 50 caliber muzzle devices—and ships with a flash suppressor.

In addition, the rifle comes with a lightweight aluminum receiver with grooves cut into the front of the mag well and in front of the trigger; M-LOK forend with a full Picatinny rail; adjustable gas block so you can run subsonic loads using a suppressor; Adaptive Tactical EX Performance adjustable buttstock; front and rear sling swivel mounts; and a five-round capacity.

“The Big Horn Armory AR500 rifle is capable of taking any big game animal,” the press release asserts. “For law enforcement or military use, the AR500 is the ultimate checkpoint duty rifle replacing the .50 Beowulf, or CQC rifle in a short barrel configuration, or as a powerful breaching weapon capable of clearing any obstruction, including bullet proof glass.”

The MSRP on the Big Horn Armory AR500 in 500 Auto Max is $1,999. See the specs and videos below.

For more information about Big Horn Armory, visit

Big Horn Armory AR500 Specifications

  • Caliber: 500 Auto Max
  • Rate of Twist: 1 in 24
  • Barrel Length: 18 inches
  • Muzzle: Threaded
  • Crown: Recessed
  • Butt Stock: Adaptive Tactical EX Performance M4-style stock of high-impact polymer, collapsible and adjustable
  • Fore end: MLOK with full Picatinny rail
  • Action Materials: 7075 Aluminum hard anodized
  • Metal Finishes: Hunter Black Nitride on SS parts
  • Swing Swivel Mounts: Integral front and rear
  • Mag Capacity: 5
  • Length of Pull: Adjustable
  • Overall Length: Varies
  • Weight: 9.55 lbs.
  • MSRP: $1,999

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