US Patent 9777975 Semiautomatic firearm

A semiautomatic firearm is presented that is a combination of known parts from the AR-15 style firearms and AK-47 style firearms and new parts. The firearm includes a receiver and a removable trunnion inserted into the receiver. A barrel is threaded and pinned into the trunnion and an adjustable gas block is connected to the barrel. The gas block includes a gas bore and an adjustable member that extends into and out of the gas bore thereby adjusting the amount of gases that travel through the gas block. The firearm also includes a foregrip installed over the barrel and gas block. The foregrip has a pattern of venting openings therein and an opening that provides access to the adjustable member of the gas block as well as a top rail and a bottom rail. The combination of these components provides a semiautomatic firearm that operates smoothly while being rugged and durable.