This rifle is designed to fire a cartridge based on the 20x110mm Vulcan Cannon cartridge, shortened, and necked up to match a .950 caliber (24.1mm) cast lead bullet. The round is large enough that when developed by J.D. Jones of SSK industries, they had to receive a "Sporting Use Exception" from the ATF to deregulate the rifles. SSK Industries manufactured only three of these rifles, and as of 2014 SSK no longer produced ammunition for it. The barrel is marked "SSK 950 JDJ Gun Number One" in fancy script lettering on the left side. The receiver is marked "FAT MAC" above the serial number on the left side. The rifle weighs an astounding scale-breaking 61 pounds! Includes two reloading dies, approximately 15 loaded rounds, 63 empty casings, two wood loading blocks, and nearly 90 cast lead bullets.

Excellent overall with original finish, some scattered light pitting on the barrel and handling marks overall. The stock has a few areas of wear mostly confined to the underside, and grip areas. Mechanically excellent.