Big Horn Armory AR500 in 500 Auto Max

The most powerful AR on the planet in 500 Auto Max available for big game hunters and law enforcement alike. 

Big Horn Armory AR500 in 500 Auto Max
Big Horn Armory AR500 in 500 Auto Max

Cody, Wyo. ( – Big Horn Armory, makers of big-bore firearms, introduced their latest big bore gun in a completely different platform from their other models earlier this year: the AR platform. The Big Horn Armory AR500 in 500 Auto Max is available to big game hunters, big bore aficionados and law enforcement.

The gas operated AR500 was designed and produced by Big Horn Armory in the USA and is based on a DPMS style AR 308. The lightweight aluminum receiver features grooves cut into the front of the mag well for a confident grip and additional grooves in the front of the trigger to allow a finger rest while not firing. All steel parts have been salt-bath nitrite finished for corrosion resistance.

“All we do at Big Horn Armory is design and make big bore guns,” Greg Buchel, president of Big Horn Armory, 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.”

The 500 Auto Max was developed by Big Horn Armory using a 500 S&W rimless straight walled casing. With a variety of loads available, the 500 Auto Max can exceed 4,000 FPE easily, making it the choice for Dangerous Game, world-wide.

The AR500’s precision machined stainless steel barrels are surface hardened to Rc82 with Big Horn Armory’s Nitride process for consistent downrange performance and in-the-field dependability. The 18-inch barrel is threaded at a ¾-inch x 28 TPI, standard for most 50 caliber muzzle devices and ships with a standard flash suppressor.

Big Horn Armory’s 500 Auto Max is a rimless version of the 500 S&W with the same ballistics. It is capable of feeding and firing any .500 diameter bullet between 200 and 700 grains. The AR500 has an adjustable gas block to allow the user to run sub sonic loads using a suppressor. 500 Auto Max ammunition is currently shipping from Buffalo Bore and Underwood Ammo. It is also available at Midway USA.

AR500 Left Side View
AR500 Left Side View

The Big Horn Armory AR500 rifle is capable of taking any big game animal. 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.

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: $1,999.00

For more on Big Horn Armory, visit or any of their social media platforms: Facebook, Instagram, YouTube or Twitter.

About Big Horn Armory:Big Horn Armory

Big Horn Armory was founded in 2008 with the expressed intention of designing a Browning-type lever-action gun chambered in 500 Smith & Wesson Magnum. The Big Horn Armory Model 89, made in America, closely follows the work of John Browning with refinements courtesy of modern metallurgy and machining capabilities. The first rifles began shipping in September of 2012 and since then, BHA has added to their big bore lineup with a Model 90 Carbine in 460 S&W, the Model 90A in 454 Casull, the Model 90B in .45 Colt, the Model 89A in 500 Linebaugh and the Model 89B in .475 Linebaugh. In 2017, Big Horn Armory took a departure from its lever-action series and developed the AR500 Auto Max, the most powerful short-range, semi-auto based on an AR .308 platform.

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    scotty GunnBryonWalt Kuleck Recent comment authors
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    scotty Gunn
    scotty Gunn

    Only two grand? Why, I will take two, the mrs. will be jealous otherwise.

    Walt Kuleck
    Walt Kuleck

    Cool! One query: why does the lead picture depict what appears to be an AR-15 (5.56)-type mag, while the shot below pictures an SR-25 (7.62)-type mag?


    The above pic is a production rifle and the pic below is a prototype that used a modified AR10 mag. Big Horn Armory opted to go with an AR15 mag well in the receiver to utilize the Beowulf magazines that are already available and require no modification to work as the AR10 magazines were a bit too long for the OAL of the cartridge to function smoothly, which required an insert to allow it to function properly. It was less work to change the design slightly on the receiver to a AR15 mag well.