In the world of firearms, where power is a common trait, the .950 JDJ rifle cartridge distinguishes itself as a colossus among the mighty.
Developed by J. D. Jones of SSK Industries, this massive cartridge is not only impressive in its dimensions but also in its performance, boasting ballistics that come startlingly close to those of World War I tank rounds.
Crafted from a 20×102mm Vulcan cannon case, shortened and necked up to fit a .950 inch (24.1 mm) bullet, the .950 JDJ is a cartridge that redefines large caliber.
The projectiles for this behemoth weigh in at a staggering 3,600 grains, or 8.2 ounces—over half a pound of pure stopping power.
The result is a muzzle energy of 38,685 foot-pounds force (ft·lbf), thrusting these colossal rounds at speeds of approximately 2,200 feet per second (ft/s).
This extraordinary cartridge propels its projectiles with such force that it rivals the energy of a 2,800-pound automobile traveling at 20 miles per hour.
By comparison, the 5.56×45mm NATO round—a staple in military service rifles—produces between 1,200 and 1,300 ft·lbf, while the .308 Winchester—a favorite among hunters and snipers—generates between 2,000 and 3,000 ft·lbf, depending on the load.
But with great power comes great recoil. The .950 JDJ generates over 200 ft·lbf of free recoil energy, well beyond the capacity of almost any shooter to handle from the shoulder.
This necessitates the use of heavy “lead sled” or similar shooting rest to manage the recoil and avoid injury.
Rifles chambered for the .950 JDJ are themselves behemoths, with weights ranging from 85 to 110 pounds, depending on configuration, and feature extraordinarily thick Krieger barrels equipped with massive 18-pound muzzle brakes.
The rifles’ exceptional size and cost—the rifles themselves can fetch around $8,000, and each loaded cartridge costs $40.
They are often referred to as “range queens,” signifying rifles that are primarily taken to the shooting range for recreational purposes rather than being utilized for hunting or other practical applications.
In the United States, a rifle of this caliber would normally fall under the category of a Destructive Device.
However, SSK Industries was granted a “Sporting Use Exception,” allowing these rifles to be purchased and owned like any other Title I rifle, provided the buyer is over 18 and has no felonies on their record.
The rarity of the .950 JDJ is also notable. SSK Industries produced only three of these rifles, and as of 2014, no longer manufactures ammunition for them.
Relevant articles:
– .950 JDJ, Military Wiki | Fandom
– POTD: Largest Sporting Rifle Cartridge Ever Made – .950 JDJ, AllOutdoor.com, Oct 6, 2022
– Collectible Firearms for Serious Gun Collectors, Rock Island Auction, Jan 8, 2024