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.450/400 BPE 2 3/8" is obsolete; typical availability is antique.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.

Lindcott Armory

Rifle · Obsolete / Non-standard

.450/400 BPE 2 3/8"

Also known as .450/400 Black Powder Express 2 3/8" · 450/400 BPE 2 3/8" · .450/400 BPE

Black Powder Express cartridge in the .450/400 family, 2 3/8 inch case.

Caliber: 0.4067″ · 10.33 mm
Introduced: 1880
Case: Rimmed
Primary use: hunting
Status: Obsolete

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VelocityBeing verified

EnergyBeing verified

Identity

Introduced: 1880
Type: Rifle
Origin: United Kingdom
Inventor: Various British
Manufacturer: British gunsmiths / Kynoch
Standard: Obsolete / Non-standard
Status: Obsolete
Availability: Antique

Build

Case capacity: 65 gr H₂O
Twist (typical): 1:16
Primer: Large Rifle
Case type: Rimmed

Pressure & range

Max pressure: 18,000 psi
Eff. range: 150 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.

Performance

Best for Withheld until verified

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 ⌀	15.65	0.616	·
Belt ⌀	n/a
Rim thickness	1.07	0.042	·
Neck length	13.70	0.539	≈
Case length	60.65	2.388	·
Overall length	—	—

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

Verification

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.

Powder $/lb Charge (gr) Bullet $/ea Primer $/ea Brass reuses Brass $/ea

Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.

Connected reference

Loads6 factory loads for .450/400 BPE 2 3/8"FirearmsFirearms in .450/400 BPE 2 3/8"

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.

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 →