You talking about the M3a1 Bob ?

I carried one of these for a couple of years when I first got to Fort Riley. Standard issue to the M60A1 Tankers. Dangerous hunk of tin. Looked like it was made by the chinese from soup cans. I don't think I ever fired it without having a runaway and you only had two choices when that happened. Hang on to the damn thing until all 30 rounds discharged or try and slam the cover shut and hope it didn't break the tab off that held the bolt back. You couldn't get a more simple weapon, unless of course you were willing to bang your 45 rounds with a rock.