JD Jones’ .950 JDJ cartridge is a generally described as the largest sporting rifle cartridge ever produced, producing more energy than even the 4-bore cartridges that match it in bore diameter. Only three of these rifles were made, and the original loading was a 2600 grain (168g) cast bullet moving at 2200 fps (670m/s), for a whopping 28,000 foot-pounds of muzzle energy (38kJ). There are some antitank rifles that produce more, but nothing comparable in both energy and bore diameter in the sporting realm.

The rifle is built on a McMillan stock and action, and was originally produced on special order for a customer who wanted a really (really) big rifle that could use cast bullets. The cartridge cases were originally made from 20mm Vulcan cases trimmer down to a (mere) 70mm case length, with custom made lathe-turned cases replacing them when brass Vulcan cases became too difficult to source. The gun itself weighs a bit over 60 pounds, with nearly a third of that in the muzzle brake alone. This example is being sold with a whole bunch of ammunition components, which is a good thing since Jones/SSK stopped making the ammunition several years ago…