Meet the world’s most powerful AR

“We were not content with the big bore cartridge offerings available in the AR platform, so we made our own,” says the BHA team. 

The logical choice was something to match the power and versatility of the company’s Model 89 Lever Action in 500 Smith & Wesson Magnum. The result was development of the 500 Auto Max, a rimless 500S&W magnum to feed in a semi-automatic rifle. 

“Our bold AR design and big bore 500 Auto Max cartridge put an unparalleled amount of power into a pleasant shooting, rapid firing, versatile rifle,” continued the BHA team. 

“This combination of size, familiar manual-of-arms, available accessories and energy on target make the AR500 Rifle ready to handle almost any situation. The AR500 is also available in a braced-pistol configuration!”      

The 500 Auto Max is a rimless 500 S&W Magnum that is easy to use and reload. A very versatile cartridge, it can be used with loaded ammunition with bullets ranging from 350grns to an amazing 600grns. The handloader can utilize bullets ranging from 275grns to 700grns in almost any bullet type imaginable - hardcast, jacket hollow points, monolithic solids, etc.  This unprecedented range of bullets weight and design make the AR500 suitable for anything from prairie dogs to pachyderms to Peterbilts. “Truck stopping power in a platform weighing less than 10 pounds,” says the BHA team.


Big Horn Armory AR500 Rifle Specifications:

Caliber: 500 Auto Max

Rate of Twist: 1 in 24 Barrel

Length: 18”

Muzzle: Threaded w/ muzzle brake

Crown: Recessed

Butt Stock: Adjustable butt stock

Fore-end: M-LOK free float handguard

Action Materials: 7075 Aluminium hard anodized

Metal Finishes: Hunter Black Nitride on SS parts

Swing Swivel Mounts: Integral rear

Mag Capacity: 5 rd standard or 9 rd option

Overall Length: Varies

Weight: 9 lb.


Big Horn Armory likes to think big. As a result, the company isn’t your average gun manufacturer. Since they are gun guys like you and your customers, they only build guns that give a reason to jump out of bed in the morning. For Big Horn, that means the bigger the better. Whether it’s packing 36,800 ft lbs of energy in a lever action, or building the most powerful AR on the market, the company’s goal is to give your customers the biggest bang for their buck. Literally. At the end of the day, that’s why they’re in the business. To build guns your customers can’t wait to shoot.