The Adams Arms Retro-Fit Piston Drive System uses the same gas port on the barrel to work the action of our inverted piston. Instead of directing the gases into the receiver, they go into a gas plug and drive rod sleeve invented by Adams Arms. The gases are contained inside the drive rod sleeve and push the bolt carrier rearward using the gas pressure to cycle the action.
Adams Arms proprietary operating systems mechanically actuate the bolt carrier external of the receiver. This keeps the internal receiver and all the critical moving parts clean and free from heat and carbon build up.
Here are some of the main differences when using the Adams Arms Operating System: