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Lindcott Armory

Revolver · Obsolete

.455 Webley Mk II

Webley's semi-automatic pistol cartridge for the Webley Self-Loading Pistol adopted by the Royal Flying Corps.

Caliber
0.4555″ · 11.57 mm
Introduced
1912
Case
Rimmed
Primary use
Self-Defense
Status
Discontinued

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VelocityBeing verified
EnergyBeing verified
Typical grains262 · 265 gr
Identity
Introduced
1912
Type
Revolver
Origin
United Kingdom
Inventor
Webley & Scott
Manufacturer
Webley & Scott
Standard
Obsolete
Status
Discontinued
Availability
Collector
Build
Case capacity
25 gr H₂O
Twist (typical)
1:20
Primer
Boxer Small Pistol
Case type
Rimmed
Pressure & range
Max pressure
13,000 psi
Eff. range
50 yd
Recoil
2.5–3.5 ft·lb
Subsonic
Capable

Introduced by Webley & Scott

Ballistics

Published velocity/energy data isn't available for .455 Webley Mk II — an obsolete/collector cartridge.

Performance

Best for Withheld until verified
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.

CIP TDCC · approximate
Measuremmin✓
Bullet ⌀ 11.570.456 ~
Neck ⌀ 12.140.478 ✓
Shoulder ⌀ n/a
Shoulder angle n/a
Base ⌀ 12.150.478 ✓
Rim ⌀ 13.500.531 ✓
Belt ⌀ n/a
Rim thickness 1.000.039 ✓
Neck length n/a
Case length 19.500.768 ✓
Overall length 32.001.260 ~

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. .455 Webley Mk II 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.

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

Connected reference

FirearmsFirearms in .455 Webley Mk II

History

Webley developed these semi-automatic pistol cartridges for British military trials during WWI. The .455 Webley Self-Loading Pistol was adopted by the Royal Navy and Royal Flying Corps. The cartridge's semi-rimless design improved feeding reliability in semi-automatic actions compared to the rimmed .455 Webley revolver round.

FAQs

What twist rate does .455 Webley Mk II use?
.455 Webley Mk II typically uses a 1:20 twist rate.
What bullet diameter is .455 Webley Mk II?
.455 Webley Mk II uses a 0.4555″ (11.57 mm) diameter bullet.
Is .455 Webley Mk II still in production?
.455 Webley Mk II is discontinued; typical availability is collector.
What is .455 Webley Mk II used for?
.455 Webley Mk II is primarily used for self-defense.

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 →