I have been thinking of building a rifle on the AR platform and I was thinking of building one in a Large caliber. I have found .450 Bushmaster, .458 SOCOM, and .50 Beowulf. Does anyone on here have any experience with one or more of these calibers or have another caliber that I might have overlooked? I've got an AR chambered for .223 Remington/5.56x45mm NATO already, and I am getting parts for a .308 Winchester/7.62x51mm NATO build from a friend that started adn never finished. (He does that a lot, starts and never finishes projects.) I just thought that I "Big" AR would be nice to have with the other two "Little" brothers, or am I wasting my time and money and should just stick to the 5.56 and the 7.62?