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Lindcott Armory

Rifle · SAAMI

.375 Winchester

Also known as .375 Win · 9.5x51mmR

The original Winchester Big Bore cartridge — parent case for the .307 and .356 Winchester.

Caliber
0.376″ · 9.55 mm
Introduced
1978
Case
Rimmed
Parent
.38-55 Winchester
Primary use
Hunting
Status
Active

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VelocityBeing verified
EnergyBeing verified
Typical grains200 · 220 · 250 gr
Identity
Introduced
1978
Type
Rifle
Origin
United States
Inventor
Winchester
Manufacturer
Winchester Ammunition
Standard
SAAMI
Status
Active
Availability
Limited
Build
Case capacity
52 gr H₂O
Twist (typical)
1:12
Primer
Large Rifle
Case type
Rimmed
Pressure & range
Max pressure
52,000 psi
Eff. range
200 yd
Max range
400 yd
Recoil
12–18 ft·lb

Introduced by Winchester Ammunition

Ballistics

Published velocity/energy data isn't available for .375 Winchester. Parent case: .38-55 Winchester.

Performance

Best for Withheld until verified
Best for Withheld until verified
Dimensionscase measurements · scale drawing · size vs familiar rounds

Case dimensions — the scale drawing at the top of the page is built from these.

CIP TDCC · verified
Measuremmin✓
Bullet ⌀ 9.550.376 ✓
Neck ⌀ 10.160.400 ✓
Shoulder ⌀ n/a
Shoulder angle n/a
Base ⌀ 10.710.422 ✓
Rim ⌀ 12.850.506 ✓
Belt ⌀ n/a
Rim thickness 1.600.063 ✓
Neck length n/a
Case length 51.312.020 ✓
Overall length 65.022.560 ✓

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 Winchester is highlighted below.

Factory loads

Verification

Being verified

Advertised FPS, energy, and BC are withheld until loads clear verification.

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.

Firearms chambered in .375 Winchester

4 models in the database chamber .375 Winchester. Browse all →

Winchester Model 94 Big Bore .375 WinWinchester Repeating Arms Model 70 Alaskan .375 Win 25-inchRuger No. 3Thompson/Center Contender G1 45-70 Govt 12-inch

Lineage

Immediate parent
.38-55 Winchester
Family TreeOpen .375 Winchester in the interactive cartridge family tree

Connected reference

Loads16 factory loads for .375 WinchesterFirearmsFirearms in .375 Winchester

History

Introduced in 1978 for the Winchester Model 94 Big Bore — a strengthened version of the classic Model 94 capable of handling higher-pressure cartridges. The .375 Winchester launched the Big Bore family; the .307 and .356 Winchester followed in 1982 as rimmed versions of .308 and .356. Factory ammunition remains available from Winchester. The Big Bore 94s are valued by hunters who want a powerful, compact lever-action.

FAQs

What twist rate does .375 Winchester use?
.375 Winchester typically uses a 1:12 twist rate.
What bullet diameter is .375 Winchester?
.375 Winchester uses a 0.376″ (9.55 mm) diameter bullet.
Is .375 Winchester still in production?
.375 Winchester is active; typical availability is limited.
What is .375 Winchester used for?
.375 Winchester is primarily used for hunting.
What is .375 Winchester based on?
.375 Winchester is derived from the .38-55 Winchester case.

Sources & provenance

Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 16 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →