Some background info on M1
Unlike modern carbines based on shortened version of assault rifles (M4 from M16, ASK-74U from ASK-74, and of course our trusty L22 from the L85) M1 carbine is completely unrelated to the M1 Garand. It was purpose designed as a smaller defense weapon for second line troops and specialist frontline troops (you know, like commandos and paratroopers) who needed a gun smaller and lighter than a standard battle rifle but with more firepower than pistols or submachine guns.
Now before anyone says semi-automatic rifles = sharpshooter, have a look at this picture:
On the left is .30 carbine rounds specially developed for the M1. Centre is 7.62x39mm of AK-47, and right is 5.56 NATO used in the bullpup. As you can see, .30 carbine is in no way an assault rifle round, it’s actually more of a supersized pistol round with its straight wall and round nose bullet. Without a spitzer (ie, pointed) bullet, the M1 carbine is only good for about 270m. Which is fine as personal defense for rear troops and spec-op missions tend to happen at fairly close range anyway.
Due to its versatility, easy of handling, relative low cost and easily available ammo, it’s recommended by The Zombie Survival Guide as one of the two weapons most suited for a zombie outbreak situation. (The other is the machete)