Abstract: A gas system for a firearm having a gas block coupled to a barrel with a gas capture port in communication with a barrel gas port. A sleeve removeably mounted inside the gas block has: a gas conduit; a seat near the gas conduit; a projection; and a rod conduit communicating gas through the projection. A rod movably mounted in the gas block has a cup fitting over the projection. A valve has a knob coupleable to the gas block and a plug moveable within the pressure sleeve with a plunger engageable with the seat to adjust gas flow through the gas conduit to the rod conduit. Gas discharged from a fired cartridge flows against the cup to drive the rod to reload the firearm. The plug is moveable by the knob to a plurality of positions to alter the gas conveyed to the rod.

Abstract: A gas system for a firearm having a gas block coupled to a barrel with a gas capture port in communication with a barrel gas port. A sleeve removeably mounted inside the gas block has: a gas conduit; a seat near the gas conduit; a projection; and a rod conduit communicating gas through the projection. A rod movably mounted in the gas block has a cup fitting over the projection. A valve has a knob coupleable to the gas block and a plug moveable within the pressure sleeve with a plunger engageable with the seat to adjust gas flow through the gas conduit to the rod conduit. Gas discharged from a fired cartridge flows against the cup to drive the rod to reload the firearm. The plug is moveable by the knob to a plurality of positions to alter the gas conveyed to the rod.