The .950 JDJ is among the world’s most-powerful, and largest-caliber, rifle cartridges. Loaded .950 JDJ cartridges are approximately the length of an empty .50 BMG casing (i.e., 4″), and are based on a 20mm Vulcan case shortened and necked up to accept the .950″ bullet. Projectiles are custom-made and most commonly weigh 3,600 grains (8.2 ounces, or over half a pound).

.950 JDJ cartridge wiki – HERE

As its name implies, rifles chambered for the cartridge have a bore diameter of 0.950″, which would normally classify them as Destructive Devices under the 1934 National Firearms Act. However, SSK sought and received a “Sporting Use Exception” to de-regulate the rifles, meaning they can be purchased like any other rifle by a person over age 18 with no felonious criminal record. The rifles themselves use McMillan stocks and extraordinarily thick Krieger barrels bearing an 18 lb (8.2 kg) muzzle brake. Overall, depending on options, the rifles weigh between 80 and 110 pounds and are therefore only useful for shooting from a bench rest or heavy bipod. Despite the weight, recoil is significant. muzzle energy of 38,685 ft·lbf (52,450 J). For comparison, the 5.56×45 cartridge, used in the AR-15 rifle, produces approximately 1,200–1,300 ft·lbf. The .308 Winchester, a favorite for hunters and medium-range police/military sniping, produces between 2,000 and 3,000 ft·lbf (4,100 J) depending on the load used. The rifles cost $8,000, loaded cartridges are $40 each.

I can’t believe the muzzle energy on that thing… that is NUTS.

As cool as this is, I much would rather have a .50 caliber Barrett for so many reasons.

If you are interested in purchasing one of these guns contact The McBros Rifle Co. – HERE

The rifle cartridges are available at SSK Industries – HERE

Thanks to Jim for the info.