Rifle · SAAMI
.338 Weatherby RPM
Efficient, rebated-rim .338 Weatherby cartridge for lightweight six-lug Mark V rifles..
- Caliber
- 0.3383″ · 8.593 mm
- Introduced
- 2022
- Case
- Rebated
- Parent
- 6.5mm Weatherby RPM
- Primary use
- Hunting
- Status
- Active
- Introduced
- 2022
- Type
- Rifle
- Origin
- United States
- Inventor
- Weatherby
- Manufacturer
- Weatherby
- Standard
- SAAMI
- Status
- Active
- Availability
- Limited
- Primer
- Large Rifle Magnum
- Case type
- Rebated
- Max pressure
- 65,000 psi
- Eff. range
- 500 yd
Introduced by Weatherby
Ballistics
Velocity only, no drag model: no published ballistic coefficient is on file for .338 Weatherby RPM, 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
- 6.5mm Weatherby RPM
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.
SAAMI · verified| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 8.59 | 0.338 | ✓ |
| Neck ⌀ | 9.25 | 0.364 | ✓ |
| Shoulder ⌀ | 12.04 | 0.474 | ✓ |
| Shoulder angle | 35° | — | ✓ |
| Base ⌀ | 12.70 | 0.500 | ✓ |
| Rim ⌀ | 12.01 | 0.473 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.37 | 0.054 | ~ |
| Neck length | 7.92 | 0.312 | ≈ |
| Case length | 64.77 | 2.550 | ✓ |
| Overall length | 85.85 | 3.380 | ✓ |
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 Weatherby RPM 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
Introduced 2022 as the second Weatherby RPM-family cartridge (SAAMI drawing May 2022); MAP 65,000 psi.
FAQs
- What bullet diameter is .338 Weatherby RPM?
- .338 Weatherby RPM uses a 0.3383″ (8.593 mm) diameter bullet.
- Is .338 Weatherby RPM still in production?
- .338 Weatherby RPM is active; typical availability is limited.
- What is .338 Weatherby RPM used for?
- .338 Weatherby RPM is primarily used for hunting.
- What is .338 Weatherby RPM based on?
- .338 Weatherby RPM is derived from the 6.5mm Weatherby RPM 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 →