[1] During the mid-1970s, China decided to develop a lighter 12.7 mm machine gun to replace the Type 54 (indigenous DShK) that was more suited for mobile anti-aircraft applications.

To save weight the Type 77 used a hybrid short-recoil and direct gas impingement operated action,[2] somewhat unusual for a machine gun, resulting in few moving parts and a long and slim, tubular receiver.

Overall weight of the gun and tripod comes to about 56 kg (120 lb), less than half that of a mounted Type 54/DShK, though it retains the same locking system and belt feed.

The barrel is also thinner as light weight was favored over volume of fire, which causes it to overheat faster, with a prominent "pepperpot" muzzle brake.

The gun also has a large charging handle below the receiver, shoulder stock, and fires from an open bolt.