NAME – 7.62x42mm SP-4

NAME (COMMON) – SP-4 Silent Cartridge – Spetsial’nyy kartridzh 4 [Special Cartridge 4]

TYPE – Captured piston suppressed cartridge

YEAR OF INTRODUCTION – 1983

COUNTRY OF ORIGIN – USSR

CASE TYPE – Rimless bottleneck

CARTRIDGE LENGTH – 41.9 mm (1.65 in)

CASING LENGTH – 41.9 mm (1.65 in)

BULLET TYPE – Flat nosed steel cylinder

BULLET DIAMETER – 7.59 mm (0.299 in) [Body], 7.82 mm (0.308 in) [Rotating/Driving Band]

BULLET LENGTH – 28.4 mm (1.12 in)

BULLET WEIGHT – 9.97 g (153.8 grains)

POWDER WEIGHT – 0.23 g (3.5 grains)

CASING WEIGHT – 6.95 g (107.3 grains) with piston

TOTAL ROUND WEIGHT – 23.2 g (358 grains)

MUZZLE VELOCITY – 189 m/s (621 fps)

MUZZLE ENERGY – 180 j (133 ft/lb)

Piston – 8.91mm dia, 5-8mm long

124.6 ave db