I'm toyin with the idea of buildin a 450. Kinda expensive but the guys I know who have one have nothing but love for em.
(Cabela's Ad)Bushmaster .450
It’s called "Thumper" and it’s capable of taking any game animal in North America. Engineered to mount on your mil-spec AR-15 lower, this 20" model hurls the 250-grain Hornady SST/FT .450 Bushmaster bullet downrange at 2,200 fps. Though not designed as a long-range caliber, there’s nothing on this continent capable of standing up to the firepower of Thumper and inside 200 yards its accuracy is outstanding. Recoil has been compared to that of a 20-gauge shotgun. A tubular-aluminum forend allows the barrel to free-float from the nut forward to enhance accuracy. Chrome lining in both the bore and chamber makes the .450 Bushmaster easy to clean and extends barrel life. A five-round magazine is included.