Re: M2 carbines
The Israelis apparently agree the the .30 Carbine may be the best sub-gun of all time - they have some kind of bullpup set-up with a M2 carbine in it. I spotted it being carried by a 'secret service'-type in a picture from Israel awhile back. While mediocre as a battle rifle (which it was never intended to be), the carbine is smashing as a sub-gun. I think the M1 is tops as a home defense gun too, particularly in a folding or collapsible stock.