Still using M1/M2 carbines in the year 2024?
Did anyone notice the surviving human civilization is still using M1/M2 carbines from World War II? Is that the best they can do in the year 2024? At least by 1960 the U.S. Army was using M14 semiautomatic rifles. The AR 15 had been designed in 1957 but I think by 1960 it was still in development as the AR 10, chambered for the 7.62mm x 51mm NATO cartridge, known in the USA as, .308.
I'm presuming that Hollywood could have at least designed some futuristic military firearms for the movie. It wouldn't have been all that difficult nor expensive.