Pistol · Proprietary

.375 JDJ

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
Velocity1,500–1,800 fps
Energy1,100–1,943 ft·lb
Identity
Introduced
1979
Type
Pistol
Origin
United States
Inventor
J.D. Jones
Manufacturer
SSK Industries
Standard
Proprietary
Status
Active
Availability
Rare
Build
Primer
Large Pistol
Case type
Rimmed
Pressure & range
Max pressure
42,000 psi
Eff. range
150 yd
Max range
300 yd

Ballistics

Representative trajectory · 100 yd zero0–500 yd
100 yd · zero0″−107″107″ drop @ 500 yd0250500Open 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
Measuremmin
Bullet ⌀9.530.375·
Neck ⌀10.080.397·
Shoulder ⌀11.480.452·
Shoulder angle23.3°~
Base ⌀11.940.470·
Rim ⌀13.060.514·
Belt ⌀n/a
Rim thickness1.570.062·
Neck length9.320.367
Case length56.902.240~
Overall length75.572.975·

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

Immediate parent
Family TreeOpen .375 JDJ in the interactive cartridge family tree

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 →