1) Random pulse discrimination 
Random Pulse Discrimination
The RPD is a Soviet gas operated automatic light machine gun first developed during 1943 as a machine-gun to utilise the then new 7.62 mm x 39 cartridge. The RPD took a 100-round disintegrating link belt feed carried in a drum and fired with a cyclic rate of 700 rounds per minute and a muzzle velocity of 700 meters per second to an effective range ...