Feed is from a curved 30 round staggered box magazines inserted from the top of the receiver. A folding wood and metal carrying handle is attached to the barrel for easy barrel change. The barrel is heavily finned and can easily be removed for replacement or maintenance. The locking system features a tilting bolt locking block located in the receiver below the bolt and operated by an inclined surface on the gas piston rod. A manual gas regulator with five settings is attached to the barrel.

The gas system utilises a long stroke piston located below the barrel. All metal construction apart from the wooden butt, pistol grip and carry handle. The Type 99 light machine gun is an automatic gas operated weapon.