Piston for a gas-operated firearm

A piston for a gas operated firearm having a gas block defining a cylindrical bore having a bore axis in communication with a barrel bore and an open end of the cylindrical bore facing a rearward direction toward an operating system, the piston comprising:

• an elongated body having a head portion adapted to be closely received in the cylindrical bore for reciprocation within the bore;
• the head portion having a first side toward a forward direction and a second side toward the rearward direction;
• the body having an operational facility on the second side adapted to transmit an operating force to the action in response to gas pressure on the first side;
• the head portion defining a bypass passage between the first side and the second side;
• wherein the passage has an inlet on the first side and an outlet on the second side, and wherein the outlet is rearward of a rear limit of the cylindrical bore.

A piston for a gas operated firearm having a gas block defining a cylindrical bore having a bore axis in communication with a barrel bore and an open end of the cylindrical bore facing a rearward direction toward an operating system, the piston comprising:

• an elongated body having a head portion adapted to be closely received in the cylindrical bore for reciprocation within the bore;
• the head portion having a first side toward a forward direction and a second side toward the rearward direction;
• the body having an operational facility on the second side adapted to transmit an operating force to the action in response to gas pressure on the first side;
• and
• the head portion defining a bypass passage between the first side and the second side, the bypass passage remaining open during all operation conditions of the firearm.