The 6.5 JDJ is a wildcat cartridge developed by J.D. Jones of SSK Industries for the Thompson/Center Contender single-shot pistol. Based on the .225 Winchester case, it is optimized for handgun hunting of medium to large game at moderate ranges.
Type: Pistol
Introduced: 1978, USA
Parent case: .225 Winchester
Standardization: Proprietary
Bullet diameter: 0.264" (6.71 mm)
Case length: 1.395" (35.43 mm)
Overall length: 1.765" (44.83 mm)
Rim type: Rimless
Primer: Large Pistol
Muzzle velocity: 1750–2100 fps
Muzzle energy: 680–1371 ft-lbs
Effective range: 100 yd
Common bullet weights: 100, 120, 140 gr
Primary use: hunting, handgun_hunting
Production status: Active
Also known as: 6.5mm JDJ
History: Developed in 1978 as part of the SSK JDJ family of Contender cartridges, the 6.5 JDJ fills the gap between smaller varmint chamberings and larger bore hunting rounds on the Contender platform. It remains one of the more popular JDJ chamberings due to the 6.5mm bullet's excellent sectional density.
Notable firearms: Thompson/Center Contender, TC Encore
Similar cartridges: .260 Remington, 6.5 Creedmoor, 7-30 Waters