NAME – 7.7x56mmR

NAME (COMMON) – 7.7mm Japanese Rimmed

TYPE – Centerfire

YEAR OF INTRODUCTION – 1929

COUNTRY OF ORIGIN – Japan

CASE TYPE – Rimmed bottleneck

CARTRIDGE LENGTH – 77.5 mm (3.05 in)

CASING LENGTH – 56.1 mm (2.21 in)

CASE HEAD DIAMETER – 11.63 mm (0.458 in)

CASE RIM DIAMETER – 13.46 mm (0.530 in)

BULLET TYPE – Composite Jacketed Spitzer

BULLET DIAMETER – 7.90 mm (0.311 in)

BULLET WEIGHT – 11.21 g (173 grains)

POWDER WEIGHT – 2.53 g (39 grains)

CASING WEIGHT – 11.02 g (170 grains)

TOTAL ROUND WEIGHT – 24.75 g (382 grains)

MUZZLE VELOCITY – 735 m/s (2411 fps)

NOMINAL BARREL LENGTH – 61 cm (24 in)

MUZZLE ENERGY – 3028 j (2233 ft/lb)

     This round is a near duplicate of the British 7.7x56mmR (.303 British) round. When the Japanese began producing the Type 92 Lewis gun under license, they also began manufacture of the round it was chambered for. In the Japanese ball round, even the unusual composite bullet of the British load has been duplicated. The Japanese Navy produced this round in multiple loadings, including: Ball, Armor Piercing, Tracer, Incendiary, and an explosive projectile.