http://www.thefirearmblog.com/blog/2...1-carbine-9mm/
I've always wanted an M1 Carbine, but I haven't really pursued it because until recently, I lived in a state that banned them by name, and I've been worried about the availability of ammo.
I'm a bit torn on this. 9mm is relatively cheap and plentiful, but at the same time, you lose a lot in terms of stopping power and range.