Patent ID: 9228786
Filing Date: 2016-01-05
CPC Classification: F41A,F41C

Claim Text:
1. A firearm comprising: a bolt carrier; a backbone configured to guide the bolt carrier; a lower receiver within which the bolt carrier is at least partially disposed, wherein the backbone is removably attached to the lower receiver; a barrel latch attached to the backbone; a barrel configured to disengage from the backbone when the barrel latch is pushed; a trigger block assembly configured to drop into the lower receiver; a gas piston having a plurality of piston rings configured to only rotate substantially in unison with one another, wherein the gas piston is configured to move the bolt carrier when a cartridge is discharged; a metered gas port disposed out of the barrel for metering gas from the barrel to the gas piston; a spring guide having a main spring disposed thereon for biasing the bolt carrier in a forward position; an anti-bounce weight at least partially contained within the spring guide; a bolt carried by the bolt carrier; an extractor attached to the bolt; two springs disposed within the bolt for biasing the extractor toward a closed position of the extractor; a bar inhibiting separation of the lower receiver and the backbone when the main spring is compressed; a firing pin disposed within the bolt; a takedown lever configured to inhibit separation of the backbone and the lower receiver, the takedown lever having a safety lock pin to inhibit inadvertent movement of the takedown lever; a charging handle configured to move rearward to move the bolt carrier from a closed bolt position to an open bolt position; a dust cover configured to open partially to allow the charging handle to move rearward and to block bolt release from open bolt position until the cocking handle has returned forward; a gas port flash suppressor configured to guide the barrel during mating of the barrel to the backbone; and a stock having a handle formed therein, wherein a projection is configured to inhibit vertical movement of a stock; and at least one of: