Rifle · Not SAAMI standardized · Not standardizedObsolete
.450/400 BPE 2 3/8"
Black Powder Express cartridge in the .450/400 family, 2 3/8 inch case.
- Caliber
- 0.4067″ · 10.33 mm
- Introduced
- 1880
- Case
- Rimmed
- Parent
- .450 Black Powder Express
- Primary use
- hunting
- Status
- Obsolete
- Obsolete
- Obsolete
- Introduced
- 1880
- Type
- Rifle
- Origin
- United Kingdom
- Inventor
- Various British
- Manufacturer
- British gunsmiths / Kynoch
- Standard
- Not SAAMI standardized · Not standardized
- SAAMI
- Not SAAMI standardized
- Obsolete
- Obsolete
- Status
- Obsolete
- Availability
- Antique
- Case capacity
- 85.5 gr H₂O
- Twist (typical)
- 1:16
- Primer
- Large Rifle
- Case type
- Rimmed
- Max pressure
- 18,000 psi, CIP transducer
- Eff. range
- 150 yd
- Max range
- 3850 yd
- Recoil
- 20–30 ft·lb
- Subsonic
- Capable
Ballistics
Published velocity/energy data isn't available for .450/400 BPE 2 3/8" — an obsolete/collector cartridge. Parent case: .450 Black Powder Express.
Performance
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
Dimensions · secondary source| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 10.33 | 0.407 | · |
| Neck ⌀ | 10.95 | 0.431 | · |
| Shoulder ⌀ | 12.75 | 0.502 | · |
| Shoulder angle | 6.9° | — | · |
| Base ⌀ | 13.80 | 0.543 | · |
| Rim ⌀ | 15.85 | 0.624 | · |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.07 | 0.042 | · |
| Neck length | 13.70 | 0.539 | ≈ |
| Case length | 60.65 | 2.388 | · |
| Overall length | 73.41 | 2.890 | |
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. .450/400 BPE 2 3/8" is highlighted below.
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.
Lineage
History
One of the earliest Nitro Express cartridges, developed in the 1890s as the transition from black powder to smokeless powder occurred in British sporting rifles. The 2 3/8" case was designed for older double rifles being converted to use the new nitro propellants. Preceded by black powder equivalents.
FAQs
- What twist rate does .450/400 BPE 2 3/8" use?
- .450/400 BPE 2 3/8" typically uses a 1:16 twist rate.
- What bullet diameter is .450/400 BPE 2 3/8"?
- .450/400 BPE 2 3/8" uses a 0.4067″ (10.33 mm) diameter bullet.
- Is .450/400 BPE 2 3/8" still in production?
- .450/400 BPE 2 3/8" is obsolete; typical availability is antique.
- What is .450/400 BPE 2 3/8" used for?
- .450/400 BPE 2 3/8" is primarily used for hunting.
- What is .450/400 BPE 2 3/8" based on?
- .450/400 BPE 2 3/8" is derived from the .450 Black Powder Express case.
Sources & provenance
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 6 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
