Pistol · Not SAAMI standardized · Not standardizedObsolete
7mm Nambu
Smaller companion to the 8mm Nambu, chambered in the 'Baby Nambu' Type B pistol issued to Japanese field-grade officers.
- Caliber
- 0.2787″ · 7.08 mm
- Introduced
- 1902
- Case
- Rimless
- Primary use
- Military
- Status
- Discontinued
- Obsolete
- Obsolete
- Introduced
- 1902
- Type
- Pistol
- Origin
- Japan
- Inventor
- Kijiro Nambu
- Manufacturer
- Japanese Arsenal
- Standard
- Not SAAMI standardized · Not standardized
- SAAMI
- Not SAAMI standardized
- Obsolete
- Obsolete
- Status
- Discontinued
- Availability
- Antique
- Case capacity
- 9.5 gr H₂O
- Twist (typical)
- 1:10
- Primer
- Small Pistol
- Case type
- Rimless
- Max pressure
- 25,000 psi, CIP transducer
- Eff. range
- 25 yd
- Max range
- 1900 yd
- Recoil
- 2 ft·lb
- Subsonic
- Capable
Introduced by Japanese Arsenal
Ballistics
Published velocity/energy data isn't available for 7mm 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.
Wikipedia · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 7.08 | 0.279 | ~ |
| Neck ⌀ | 7.64 | 0.301 | ✓ |
| Shoulder ⌀ | 8.62 | 0.339 | ✓ |
| Shoulder angle | 23° | — | |
| Base ⌀ | 8.91 | 0.351 | ✓ |
| Rim ⌀ | 9.11 | 0.359 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 0.98 | 0.039 | ✓ |
| Neck length | 7.31 | 0.288 | |
| Case length | 19.80 | 0.780 | ✓ |
| Overall length | 26.80 | 1.055 | ✓ |
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. 7mm Nambu is highlighted below.
Missing a dimension for 7mm 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 7mm Nambu
History
Developed by Kijiro Nambu alongside the Type A 'Grandpa Nambu' pistol, which used 8mm. The Type B 'Baby Nambu' was a scaled-down version chambered in 7mm, issued to officers who wanted a smaller sidearm. Production was limited and the cartridge never achieved widespread adoption. Original specimens and ammunition are extremely rare collector items. The Baby Nambu is considered one of the most beautiful Japanese pistol designs.
FAQs
- What twist rate does 7mm Nambu use?
- 7mm Nambu typically uses a 1:10 twist rate.
- What bullet diameter is 7mm Nambu?
- 7mm Nambu uses a 0.2787″ (7.08 mm) diameter bullet.
- Is 7mm Nambu still in production?
- 7mm Nambu is discontinued; typical availability is antique.
- What is 7mm Nambu used for?
- 7mm Nambu is primarily used for military.
Sources & provenance
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 5 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
