Laitis

"The carbine was modified from its original design to incorporate a bayonet, due to requests from the field. Very few carbines with bayonet lugs reached the front lines before the end of World War II. This modification was made to nearly all carbines during arsenal rebuild following World War II. By the time the Korean War began, the bayonet-equipped M1 was standard issue" http://en.wikipedia.org/wiki/M1_carbine The M1 Carbine did not have a bayonet lug in WWII