Pistol · Proprietary
.338 JDJ
The .338 JDJ is based on the .444 Marlin necked down to .338 caliber, delivering heavy bullet performance for a pistol cartridge.
- Caliber
- 0.338″ · 8.585 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 .338 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 ⌀ | 8.59 | 0.338 | · |
| Neck ⌀ | 9.20 | 0.362 | · |
| Shoulder ⌀ | 11.53 | 0.454 | · |
| Shoulder angle | 12.5° | — | ~ |
| Base ⌀ | 11.94 | 0.470 | · |
| Rim ⌀ | 13.06 | 0.514 | · |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.60 | 0.063 | · |
| Neck length | 5.08 | 0.200 | ≈ |
| Case length | 56.52 | 2.225 | · |
| 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. .338 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
Part of the large-bore JDJ series built on the .444 Marlin case, the .338 JDJ was designed for hunters who wanted .338-caliber bullet performance from a TC Contender or Encore. It is particularly effective on large deer, elk, and hogs at handgun ranges.
FAQs
- What bullet diameter is .338 JDJ?
- .338 JDJ uses a 0.338″ (8.585 mm) diameter bullet.
- Is .338 JDJ still in production?
- .338 JDJ is active; typical availability is rare.
- What is .338 JDJ used for?
- .338 JDJ is primarily used for hunting, handgun_hunting.
- What is .338 JDJ based on?
- .338 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 →