Take a .45 lower, add the conversion kit to make it a rifle. Looks handy. And it will definitely take a 1911 magazine, now, won't it? Can you buy a lower? Is that the receiver? Which part, here, do you think is part someone has to call NICS about? The Carbine Kit, or the pistol lower?
I'm gonna have to poke around on how people that have bought that like it...
They make a Glock version for those of you that INSIST on having a Glock.
[update: a pistol frame is a 'gun' under the law. that part has to be NICSed and form 4473ed]