|Place of origin||United States|
|Parent case||.30-06 Springfield|
|Case type||Rimless, bottleneck|
|Bullet diameter||.197 in (5.0 mm)|
|Neck diameter||.220 in (5.6 mm)|
|Shoulder diameter||.353 in (9.0 mm)|
|Base diameter||.375 in (9.5 mm)|
|Rim diameter||.376 in (9.6 mm)|
|Rim thickness||.041 in (1.0 mm)|
|Case length||1.925 in (48.9 mm)|
|Overall length||2.455 in (62.4 mm)|
|Primer type||Small Rifle|
|Maximum pressure||(around) 52,000 psi|
|Test barrel length: standard SSK-manufactured barrel
Source(s): Cartridges of the World
The .30-06 JDJ is a modified .30-06 Springfield cartridge designed to be used in the Thompson Center Arms Contender single-shot pistol. The idea behind it is to replicate the ballistics of a .30-06 fired from a rifle in a Contender pistol.
Currently, the .30-06 JDJ is not offered by any manufacturers. Cases and bullets for it can be purchased from various companies for handloaders.
Compared to a default .30-06 round, the .30-06 JDJ contains has a smaller neck that is at a 60-degree angle. However, the biggest difference is that the .30-06 JDJ has little body taper compared to the original .30-06 cartridge. This allows the .30-06 JDJ to hold an extra 5 grains of water (4.875 cm3) compared to the .30-06 Springfield, allowing one to put more gunpowder into the cartridge.
This round manages to replicate in a pistol the ballistics of a .30-06 round fired from a rifle. For example, a .30-06 JDJ cartridge with a 200-grain bullet fired from a custom Contender has a muzzle velocity of 2,504 ft/s (763 m/s), while a regular .30-06 cartridge with a 200-grain bullet with 55 grains of gunpowder has a velocity of 2,558 ft/s (780 m/s).
.30-06 JDJ cartridge next to its parent case, the .30-06 Springfield.