Patent ID: 8572875

Claim:
A firearm-magazine interface for a firearm having a spring-loaded bolt and a receiver cross-member pin, the receiver cross-member pin located in the vicinity of a magazine opening of the firearm, the firearm-magazine interface comprising: a magazine frame for receiving a magazine, the magazine frame mountable to the firearm at the magazine opening; a bolt-hold lock, the bolt-hold lock slideably interfaced to the magazine frame, a follower contact ledge of the bolt-hold lock interfaceable with a magazine follower of the magazine, the bolt-hold lock has a retracted position in which a spring-loaded bolt of the firearm freely passes by the bolt-hold lock and the bolt-hold lock has an extended position, such that when the magazine is empty, the magazine follower pushes on the follower contact ledge and the follower contact ledge lifts the bold-hold lock into the extended position, thereby a bolt catch edge of the bold-hold lock is positioned to engage with a face of the spring-loaded bolt to hold the spring-loaded bolt in an open position after a last round is fired from the magazine; a bolt release lever is moveably interfaced to the magazine frame; and a bolt-hold release paddle affixed to the bolt release lever, whereas activation of the bolt-hold release paddle rotates the bolt release lever and urges the bolt-hold lock from the extended position to the retracted position, away from the face of the spring-loaded bolt, thereby adapted to release the spring-loaded bolt; whereas the bolt-hold lock is adapted to brace against the receiver cross-member pin of the firearm, providing support to counter a force exerted by the spring-loaded bolt.