Pistol · Proprietary
.375 JDJ
The .375 JDJ is the largest of the common SSK JDJ pistol cartridges based on the .444 Marlin case, necked out to .375 caliber.
- Caliber
- 0.375″ · 9.525 mm
- Introduced
- 1979
- Case
- Rimmed
- Parent
- .444 Marlin
- Primary use
- hunting, handgun_hunting
- Status
- Active
- Introduced
- 1979
- Type
- Pistol
- Origin
- United States
- Inventor
- J.D. Jones
- Manufacturer
- SSK Industries
- Standard
- Proprietary
- Status
- Active
- Availability
- Rare
- Primer
- Large Pistol
- Case type
- Rimmed
- Max pressure
- 42,000 psi
- Eff. range
- 150 yd
- Max range
- 300 yd
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for .375 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
- .444 Marlin
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 ⌀ | 9.53 | 0.375 | · |
| Neck ⌀ | 10.08 | 0.397 | · |
| Shoulder ⌀ | 11.48 | 0.452 | · |
| Shoulder angle | 23.3° | — | ~ |
| Base ⌀ | 11.94 | 0.470 | · |
| Rim ⌀ | 13.06 | 0.514 | · |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.57 | 0.062 | · |
| Neck length | 9.32 | 0.367 | ≈ |
| Case length | 56.90 | 2.240 | ~ |
| Overall length | 75.57 | 2.975 | · |
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. .375 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 by J.D. Jones as the heavy end of his Contender cartridge family, the .375 JDJ offers impressive energy levels for a single-shot pistol. It has been used successfully on elk, moose, and bear, and sees occasional use in Africa on plains game by handgun hunters.
FAQs
- What bullet diameter is .375 JDJ?
- .375 JDJ uses a 0.375″ (9.525 mm) diameter bullet.
- Is .375 JDJ still in production?
- .375 JDJ is active; typical availability is rare.
- What is .375 JDJ used for?
- .375 JDJ is primarily used for hunting, handgun_hunting.
- What is .375 JDJ based on?
- .375 JDJ is derived from the .444 Marlin 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 →