Patent ID: 11933568
Assignee: THE UNITED STATES OF AMERICA, AS REPRESENTED BY THE SECRETARY OF THE NAVY
Field: Other special machines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 8:
9. An interchangeable modular chamber system for a firearm and one or more cartridge types comprising:
a firearm receiver comprising internal threads;
a barrel comprising a bore end, a muzzle end, a longitudinal barrel recess positioned at said bore end, external threads, and internal lands and grooves;
a chamber insert sleeve comprising a bore end, a muzzle end, a longitudinal sleeve recess positioned at said bore end, and lands and grooves;
an index pin;
a locking collar; and
a recoil lug;
wherein said chamber insert sleeve is positioned within said barrel and said index pin is inserted between said longitudinal sleeve recess and said longitudinal barrel recess at said bore end to lock and align said chamber insert sleeve with said barrel;
wherein said chamber insert sleeve is indexed such that said lands and grooves of said chamber insert sleeve align with said lands and grooves of said barrel;
wherein said chamber insert sleeve further comprises a sleeve recess and said barrel comprises a barrel recess that match a diameter of said index pin, wherein said index pin locks and aligns said lands and grooves of said chamber insert sleeve with said lands and grooves of said barrel;
wherein said locking collar and said recoil lug are threaded onto said external threads of said barrel and are positioned to set headspace for a desired cartridge;
wherein said headspace can be set in a first position to enable firing of a first cartridge type and can be set in a second position to enable firing of a second cartridge type.