The .500 Auto Max was designed by Big Horn Armory for use in their AR500 rifle, which is based on the AR-10 sized platform. The .500 Auto Max is essentially a rimless .500 S&W Magnum. It is a very versatile cartridge; it can handle anything from prairie dogs to pachyderms to Peterbilts, truck stopping power in a platform weighing less than 10 pounds. The .500 Auto Max uses the same reloading dies, shell holders & load data as the .500 S&W Mag, with the exception of requiring a taper crimp instead of the standard roll crimp. This is due to the Auto Max headspacing off of the mouth of the case instead of the rim.
Firearms are available Big Horn Armory.