Patent ID: 7721639

Claim:
An apparatus for use with a locked machine gun comprising: a casing including a first abutment part; a barrel including a second abutment part firmly connected to the barrel, wherein the second abutment part includes a curved section extending from the barrel toward a breech opening: a locking breech mechanism comprising a breech carrier and a breach head including a locking body for engagement with the first abutment part, wherein the breech head engages the curved section of the second abutment part to rotate the locking body into engagement with the first abutment part when a breech of the locked machine gun is closed, thereby locking the locking body with the first abutment part to substantially prevent rearward movement of the breach head relative to the casing during firing; and a quick-change attachment for removal of the barrel and the attachment of a new barrel, wherein the quick-change attachment rotationally fixes the barrel during firing and loading, wherein the quick-change attachment is equipped to bring about a separation between the first abutment part and the second abutment part and wherein when the barrel is replaced with the new barrel the first abutment part remains on the casing.