In 1980, Marushin developed its own closed type blowback design and it is called Plug Fire Cartridge (PFC). The cartridge has size and shape similar to real cartridges but can be screwed separable. It is made with machined brass multi-piece consisting of a simulated primer, base, piston and the "bullet". The plastic cap is plugged inside and sit on a piston which helps to keep the pressure of exploded gas to provide the blowback force. The blowback performance is much improved and cleanup is also easier.