After the war, the bayonet lug was added to lots of M1 carbines in the course of the arsenal refurbishing system. By the start of the Korean War, the bayonet lug-Outfitted M1 was standard issue. It is currently exceptional to find an initial M1 carbine without the bayonet lug. The M1 carbine mounts the M4 bayonet, which was based upon the sooner M3