Pistol · SAAMI
10mm Auto
Powerful auto pistol cartridge.
- Caliber
- 0.4004″ · 10.17 mm
- Introduced
- 1983
- Case
- Rimless
- Parent
- .30 Remington
- Primary use
- Hunting, Self Defense, Target
- Status
- Active
- Introduced
- 1983
- Type
- Pistol
- Origin
- United States
- Inventor
- Jeff Cooper / Whit Collins
- Manufacturer
- Norma
- Standard
- SAAMI
- Status
- Active
- Availability
- Common
- Case capacity
- 25.4 gr H₂O
- Twist (typical)
- 1:16
- Primer
- Large Pistol
- Case type
- Rimless
- Max pressure
- 37,500 psi, SAAMI transducer
- Eff. range
- 75 yd
- Max range
- 2250 yd
- Recoil
- 6.6–7.9 ft·lb
Introduced by Norma
Ballistics
Published velocity/energy data isn't available for 10mm Auto. Parent case: .30 Remington.
Performance
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| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 10.17 | 0.400 | ✓ |
| Neck ⌀ | 10.74 | 0.423 | ✓ |
| Shoulder ⌀ | n/a | ||
| Shoulder angle | n/a | ||
| Base ⌀ | 10.80 | 0.425 | ✓ |
| Rim ⌀ | 10.80 | 0.425 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.40 | 0.055 | ✓ |
| Neck length | n/a | ||
| Case length | 25.20 | 0.992 | ✓ |
| Overall length | 32.00 | 1.260 | ✓ |
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. 10mm Auto is highlighted below.
Factory loads
Being verified
Advertised FPS, energy, and BC are withheld until loads clear verification.
Suitable powders
20 reloading powders listed for 10mm Auto, 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.
Firearms chambered in 10mm Auto
Lineage
via .40 G&A: shortened, opened to .40
Connected reference
History
Developed in early 1980s by Jeff Cooper as ideal combat pistol cartridge. FBI adopted in 1989 but withdrew after agents complained of recoil. That failure led to .40 S&W. Cult following remains.
FAQs
- What twist rate does 10mm Auto use?
- 10mm Auto typically uses a 1:16 twist rate.
- What bullet diameter is 10mm Auto?
- 10mm Auto uses a 0.4004″ (10.17 mm) diameter bullet.
- Is 10mm Auto still in production?
- 10mm Auto is active; typical availability is common.
- What is 10mm Auto used for?
- 10mm Auto is primarily used for hunting, self defense, target.
- What is 10mm Auto based on?
- 10mm Auto is derived from the .30 Remington case.
- What are the best powders for 10mm Auto?
- Reloading powders commonly listed for 10mm Auto include Vihtavuori N320, IMR Hi-Skor 800X, CFE Pistol, Vihtavuori N340, among 20 suitable options.
Sources & provenance
- Standard C.I.P. — C.I.P. TDCC — Tables of Dimensions of Cartridges and Chambers
- Standard SAAMI — SAAMI cartridge & chamber drawing — 10mm Auto archived
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 218 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
