NAME – 7x20mm

NAME (COMMON) – 7mm Nambu

TYPE – Bottlenecked centerfire

YEAR OF INTRODUCTION – 1907

COUNTRY OF ORIGIN – Japan

CASE TYPE – Rimless bottleneck

CARTRIDGE LENGTH – 26.9 mm (1.06 in)

CASING LENGTH – 19.8 mm (0.78 in)

CASE HEAD DIAMETER – 8.92 mm (0.351 in)

CASE RIM DIAMETER – 9.12 mm (0.359 in)

BULLET TYPE – Full jacketed ball

BULLET DIAMETER – 7.19 mm (0.283 in)

BULLET WEIGHT – 3.63 g (56 grains)

POWDER WEIGHT – 0.19 g (3 grains)

CASING WEIGHT – 3.18 g (49 grains)

TOTAL ROUND WEIGHT – 7 g (108 grains)

MUZZLE VELOCITY – 320 m/s (1050 fps)

NOMINAL BARREL LENGTH – 8.6 cm (3.38 in)

MUZZLE ENERGY – 186 j (137 ft/lb)

     The 7x20mm Nambu round Is a reduced-size version of the 8x21mm Nambu round. The only weapon chambered for this diminutive was the 7mm Nambu was the “Baby” or Type B Nambu pistol. The round and its pistol were intended for commercial purchase. A number of high-ranking Japanese military officers carried the 7mm Nambu weapon for personal protection. The round is one of the very few chambered for a 7mm projectile. It has slightly greater ballistics that the  6.35×15.5mmSR (.25 ACP) round but is inferior to even the 7.65x17mmSR (.32 ACP) round.