Kind of an oddity, while it is commercial, it's built bu Erma, the same Erma that long ago built Mausers during WWII. And it looks, feels and weighs what a real M1 Carbine does. And one day on a whim, I found a bayonet mount for a real M1 an low and behold it fit. An actual M1 Carbine bayonet will fit, just loosely, the barrel fit is a little loose.
The rifles if you find one, make sure it has the orginial rear sight, most are lost for the addition of scopes. It's a costly replacement, but you can find them, the same rear sight fits an American 180, a full auto .22
Magazines are very pricey as well, once and a blue moon Numrich throws a special, half off, or about 35bucks a pop. The other aggravating thing, it likes hot ammo, no MiniMag or what not need apply, The Agulia Hypervelocity stuff is about the only ammo that will cycle it reliably, consistently mag after mag. If you put standard velocity ammo through it, it becomes a single shot.
Amongst it's family, the bottom is a Universal, yea I know, but it's an early first gen, uses USGI parts
Then a Inland-General Motors and an Underwood.