Lindcott Armory Pistol · Proprietary
7mm JDJ
The 7mm JDJ is a SSK Industries wildcat cartridge for the TC Contender, based on the .225 Winchester case necked up to 7mm.
- Caliber
- 0.284″ · 7.214 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
- Primer
- Large Pistol
- Case type
- Rimless
- Max pressure
- 42,000 psi
- Eff. range
- 200 yd
- Max range
- 250 yd
Ballistics
- 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.
SAAMI · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 7.21 | 0.284 | ~ |
| Neck ⌀ | — | — | |
| Shoulder ⌀ | — | — | |
| Shoulder angle | 40° | — | ~ |
| Base ⌀ | 10.72 | 0.422 | ~ |
| Rim ⌀ | 12.01 | 0.473 | ~ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.24 | 0.049 | ~ |
| Neck length | — | — | |
| Case length | 48.26 | 1.900 | ~ |
| Overall length | 45.09 | 1.775 | ~ |
Missing a dimension for 7mm JDJ? Some case measurements aren't in a published SAAMI/CIP drawing yet. Have a factory or reamer print? Send it → — verified hard-to-find data earns a free Lindcott sticker.
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
Part of J.D. Jones' original JDJ family designed in the late 1970s, the 7mm JDJ offers similar performance to 7-30 Waters but in a slightly different case design. It is typically ordered as a custom barrel from SSK Industries.
FAQs
- What bullet diameter is 7mm JDJ?
- 7mm JDJ uses a 0.284″ (7.214 mm) diameter bullet.
- Is 7mm JDJ still in production?
- 7mm JDJ is active; typical availability is rare.
- What is 7mm JDJ used for?
- 7mm JDJ is primarily used for hunting, handgun_hunting.
- What is 7mm JDJ based on?
- 7mm 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 →