Pistol · Obsolete / Non-standard
8mm Nambu
The Japanese military pistol cartridge — and by nearly all accounts, a catastrophically inadequate one.
- Caliber
- 0.3201″ · 8.13 mm
- Introduced
- 1906
- Case
- Rimless
- Primary use
- Military (Historical)
- Status
- Obsolete
- Introduced
- 1906
- Type
- Pistol
- Origin
- Japan
- Inventor
- Kijiro Nambu
- Manufacturer
- Tokyo Arsenal / Kokura Arsenal
- Standard
- Obsolete / Non-standard
- Status
- Obsolete
- Availability
- Collector Only
- Case capacity
- 8.2 gr H₂O
- Twist (typical)
- 1:10
- Primer
- Berdan
- Case type
- Rimless
- Max pressure
- 22,000 psi
- Eff. range
- 50 yd
- Max range
- 100 yd
- Recoil
- 2–3.5 ft·lb
- Subsonic
- Capable
Ballistics
Published velocity/energy data isn't available for 8mm Nambu — an obsolete/collector cartridge.
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 ⌀ | 8.13 | 0.320 | · |
| Neck ⌀ | 8.71 | 0.343 | · |
| Shoulder ⌀ | 10.00 | 0.394 | · |
| Shoulder angle | — | — | |
| Base ⌀ | 10.23 | 0.403 | · |
| Rim ⌀ | 10.50 | 0.413 | · |
| Belt ⌀ | n/a | ||
| Rim thickness | 0.92 | 0.036 | · |
| Neck length | — | — | |
| Case length | 21.43 | 0.844 | ~ |
| Overall length | 31.56 | 1.243 | · |
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. 8mm Nambu is highlighted below.
Missing a dimension for 8mm Nambu? Some case measurements aren't in a published SAAMI/CIP drawing yet. Have a factory or reamer print? Send it → — verified hard-to-find data earns a free Lindcott sticker.
Factory loads
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 8mm Nambu
12 models in the database chamber 8mm Nambu. Browse all →
Connected reference
History
Kijiro Nambu designed both the pistol and cartridge in the early 1900s. The Type 14 Nambu pistol saw service across all Japanese conflicts from the Russo-Japanese War through the end of WWII. The cartridge suffered from genuinely poor terminal performance — low operating pressure kept velocity down, and the small bullet weight delivered minimal energy. Japanese officers who carried the Nambu frequently complained it lacked the power to reliably incapacitate enemy soldiers. The design was never improved despite decades of documented complaints from field commanders. American accounts from the Pacific consistently describe the Nambu as 'the enemy pistol you didn't need to fear.'
FAQs
- What twist rate does 8mm Nambu use?
- 8mm Nambu typically uses a 1:10 twist rate.
- What bullet diameter is 8mm Nambu?
- 8mm Nambu uses a 0.3201″ (8.13 mm) diameter bullet.
- Is 8mm Nambu still in production?
- 8mm Nambu is obsolete; typical availability is collector only.
- What is 8mm Nambu used for?
- 8mm Nambu is primarily used for military (historical).
Sources & provenance
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 8 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →