Rifle · SAAMI standardized
.375 Weatherby Magnum
Weatherby's belted magnum cartridge for large game.
- Caliber
- 0.375″ · 9.525 mm
- Introduced
- 1944
- Case
- Belted
- Parent
- .375 H&H Magnum
- Primary use
- Hunting
- Status
- Active
- Introduced
- 1944
- Type
- Rifle
- Origin
- United States
- Inventor
- Roy Weatherby
- Manufacturer
- Weatherby
- Standard
- SAAMI standardized
- Status
- Active
- Availability
- Specialty
- Case capacity
- 110 gr H₂O
- Twist (typical)
- 1:12
- Primer
- Boxer Large Rifle
- Case type
- Belted
- Max pressure
- 62,000 psi
- Eff. range
- 400 yd
- Recoil
- 40–55 ft·lb
Introduced by Weatherby
Ballistics
Published velocity/energy data isn't available for .375 Weatherby Magnum.
Performance
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 ⌀ | 9.53 | 0.375 | · |
| Neck ⌀ | 10.21 | 0.402 | · |
| Shoulder ⌀ | 12.50 | 0.492 | · |
| Shoulder angle | 15° | — | ~ |
| Base ⌀ | 13.01 | 0.512 | · |
| Rim ⌀ | 13.51 | 0.532 | · |
| Belt ⌀ | 13.51 | 0.532 | ~ |
| Rim thickness | 1.30 | 0.051 | · |
| Neck length | 11.13 | 0.438 | ≈ |
| Case length | 72.64 | 2.860 | · |
| Overall length | 91.44 | 3.600 | · |
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 Weatherby Magnum is highlighted below.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
Suitable powders
6 reloading powders listed for .375 Weatherby Magnum, fastest to slowest. Cross-reference in the finder →
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
Roy Weatherby developed this belted magnum in 1944, the first of his magnum cartridges. Based on a blown-out .300 H&H case, it delivers .375 H&H-level performance at significantly higher velocity. Commercially introduced in 1945 and remains a Weatherby signature cartridge for the largest game.
FAQs
- What twist rate does .375 Weatherby Magnum use?
- .375 Weatherby Magnum typically uses a 1:12 twist rate.
- What bullet diameter is .375 Weatherby Magnum?
- .375 Weatherby Magnum uses a 0.375″ (9.525 mm) diameter bullet.
- Is .375 Weatherby Magnum still in production?
- .375 Weatherby Magnum is active; typical availability is specialty.
- What is .375 Weatherby Magnum used for?
- .375 Weatherby Magnum is primarily used for hunting.
- What are the best powders for .375 Weatherby Magnum?
- Reloading powders commonly listed for .375 Weatherby Magnum include Norma 201, Norma 200, 203-B, Norma 202, among 6 suitable options.
Sources & provenance
- Standard SAAMI — SAAMI cartridge & chamber drawing — .375 Weatherby Magnum archived
- Standard SAAMI — ANSI/SAAMI Z299 — Cartridge & Chamber Drawings archived
- Manufacturer Wikipedia — .375 Weatherby Magnum (pointer; cites Weatherby history) · parent_cartridge
- Manufacturer Ballistic Studies Knowledgebase — .375 Weatherby Magnum · parent_cartridge
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 15 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →