NAME – 11.43×23.5mmSR

NAME (COMMON) – .455 Webley Automatic

TYPE – Semirimmed centerfire

YEAR OF INTRODUCTION – 1912

COUNTRY OF ORIGIN – Great Britain

CASE TYPE – Semi-rimmed, straight

CARTRIDGE LENGTH – 3.12 cm (1.230 in)

CASING LENGTH – 2.36 cm (0.930 in)

CASE HEAD DIAMETER – 1.1 cm (0.434 in)

CASE RIM DIAMETER – 1.27 cm (0.50 in)

BULLET TYPE – Full jacketed round nosed ball

BULLET DIAMETER – 11.56 mm (0.455 in)

BULLET WEIGHT – 14.51 g (224 grains)

POWDER WEIGHT – 0.45 g (7 grains) [Cordite]

CASING WEIGHT – 6.03 g (93 grains)

TOTAL ROUND WEIGHT – 20.99 g (324 grains)

MUZZLE VELOCITY – 216 m/s (710 fps)

NOMINAL BARREL LENGTH – 12.7 cm (5 in)

MUZZLE ENERGY – 340 j (251 ft/lb)

     Developed by the British firm Webley and Scott for their in-house design, this cartridge was only used in the Webley and Scott Mk I semiautomatic pistol. Declared obsolete at the end of WWI, the round and pistol were reissued for use in the Royal Navy during WWII.