US Patent 11187473 Firearm

A firearm includes a barrel having a breech end and a vent path through the barrel downstream from the breech end. A receiver is engaged with the breach end of the barrel and defines a chamber. A latch is connected to the receiver, and an actuator is downstream from the vent path and operably engaged with the latch. A bolt is at least partially inside the chamber. The bolt has a locked position in which the latch is engaged with the bolt to prevent the bolt from moving away from the breech end of that barrel and a released position in which the latch is not engaged with the bolt.