Pistol · Proprietary
6.5 JDJ
The 6.5 JDJ is a wildcat cartridge developed by J.D.
- Caliber
- 0.264″ · 6.706 mm
- Introduced
- 1978
- Case
- Rimless
- Parent
- .225 Winchester
- Primary use
- hunting, handgun_hunting
- Status
- Active
- Introduced
- 1978
- Type
- Pistol
- Origin
- United States
- Inventor
- J.D. Jones
- Manufacturer
- SSK Industries
- Standard
- Proprietary
- Status
- Active
- Availability
- Rare
- Case capacity
- 43.7 gr H₂O
- Twist (typical)
- 1:9
- Primer
- Large Pistol
- Case type
- Rimless
- Max pressure
- 45,000 psi, SAAMI transducer
- Eff. range
- 200 yd
- Max range
- 4050 yd
- Recoil
- 19.6–23.5 ft·lb
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for 6.5 JDJ, so this is the shape gravity alone gives the advertised velocity. Drag would steepen it. The tool below solves real loads through their published G1 or G7 model.
Open in Ballistic Compare- Parent case
- .225 Winchester
Representative trajectory — modeled from a single velocity input (no published BC for this cartridge yet).
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
reloading data · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 6.71 | 0.264 | ✓ |
| Neck ⌀ | 7.44 | 0.293 | ✓ |
| Shoulder ⌀ | 10.41 | 0.410 | ✓ |
| Shoulder angle | 40° | — | ~ |
| Base ⌀ | 10.64 | 0.419 | ✓ |
| Rim ⌀ | 11.86 | 0.467 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.24 | 0.049 | ✓ |
| Neck length | 4.83 | 0.190 | ≈ |
| Case length | 49.02 | 1.930 | ✓ |
| Overall length | 68.58 | 2.700 | ~ |
Size vs familiar rounds
Drawn at true 1:1 — every case is accurate relative to the others. Absolute size depends on your screen's pixel density, so measuring one against a real ruler may be off. 6.5 JDJ is highlighted below.
Reloading costestimate cost per round vs factory
Estimate your cost per round and how it compares to factory. Inputs are yours — nothing is stored.
Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.
Lineage
Connected reference
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.
FAQs
- What twist rate does 6.5 JDJ use?
- 6.5 JDJ typically uses a 1:9 twist rate.
- What bullet diameter is 6.5 JDJ?
- 6.5 JDJ uses a 0.264″ (6.706 mm) diameter bullet.
- Is 6.5 JDJ still in production?
- 6.5 JDJ is active; typical availability is rare.
- What is 6.5 JDJ used for?
- 6.5 JDJ is primarily used for hunting, handgun_hunting.
- What is 6.5 JDJ based on?
- 6.5 JDJ is derived from the .225 Winchester case.
Sources & provenance
Data & sources. Specs compiled from the Lindcott Armory reference; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
