Pistol · Not SAAMI standardized · Not standardizedObsolete
.455 Webley Automatic
Webley's semi-automatic pistol cartridge for the Webley Self-Loading Pistol adopted by the Royal Flying Corps.
- Caliber
- 0.455″ · 11.557 mm
- Introduced
- 1912
- Case
- Semi-Rimmed
- Primary use
- Self-Defense
- Status
- Discontinued
- Obsolete
- Obsolete
- Introduced
- 1912
- Type
- Pistol
- Origin
- United Kingdom
- Inventor
- Webley & Scott
- Manufacturer
- Webley & Scott
- Standard
- Not SAAMI standardized · Not standardized
- SAAMI
- Not SAAMI standardized
- Obsolete
- Obsolete
- Status
- Discontinued
- Availability
- Collector
- Case capacity
- 26.5 gr H₂O
- Twist (typical)
- 1:20
- Primer
- Boxer Small Pistol
- Case type
- Semi-Rimmed
- Max pressure
- 25,000 psi, CIP transducer
- Eff. range
- 50 yd
- Max range
- 1950 yd
- Recoil
- 8.4–9 ft·lb
- Subsonic
- Capable
Introduced by Webley & Scott
Ballistics
Published velocity/energy data isn't available for .455 Webley Automatic — 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.
mixed/other · approximate| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 11.56 | 0.455 | · |
| Neck ⌀ | 12.01 | 0.473 | · |
| Shoulder ⌀ | n/a | ||
| Shoulder angle | n/a | ||
| Base ⌀ | 12.04 | 0.474 | · |
| Rim ⌀ | 12.70 | 0.500 | · |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.18 | 0.046 | · |
| Neck length | n/a | ||
| Case length | 23.62 | 0.930 | ~ |
| Overall length | 31.24 | 1.230 | ~ |
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 Automatic 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.
Firearms chambered in .455 Webley Automatic
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 Automatic use?
- .455 Webley Automatic typically uses a 1:20 twist rate.
- What bullet diameter is .455 Webley Automatic?
- .455 Webley Automatic uses a 0.455″ (11.557 mm) diameter bullet.
- Is .455 Webley Automatic still in production?
- .455 Webley Automatic is discontinued; typical availability is collector.
- What is .455 Webley Automatic used for?
- .455 Webley Automatic is primarily used for self-defense.
Sources & provenance
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 9 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →
