God damn that Kingsix^H^H^H^H^H^H^H Iskaryot guy.... such a noob
If you're looking for something for gun I highly recommend the Canadian Tire Tri-Shot TM clone (S34P). They come on sale sometimes, just never pay full price for one. They sometimes break but it's not a terribly large amount of money especially if you're only using it for CQB a few times a year.
Other than that TM has an M3 obviously since there are clones of it out on the market, and I can't really say for certain about the other multi barrel shotguns but those are probably the ones to look out for.
If you're wanting a shotgun for a primary then may I suggest the gas ones like the Marushin or something (warning it'll probably be pretty expensive).