450 SMC is basically a 45 Super with a small primer pocket in the cartridge case, and using a small rifle primer instead of the large pistol primer used in the Super. The 450 SMC case is potentially slightly stronger than the 45 Super case because of having a smaller hole in it for the primer (although the added brass at the base probably doesn't really make a meaningful difference since the standard 45 Super case is not lacking in this area). The small rifle primer itself may possibly be some advantage compared with the large pistol primer in the 45 Super cartridge case if you are having issues with primer flow. Aside form those differences, the 450 SMC is loaded just barely, slightly hotter than the 45 Super (like 50 fps avg difference in velocity I believe).
The USP 45 is a BEAST, and is fine with running 45 Super even with it's stock 14 lb primary recoil spring, due to it's dual recoil-spring system. If you are running a 20 lb primary recoil spring, you are TOTALLY absolutely FINE with the 450 SMC cartridge. If I were shooting alot of 45 Super or 450 SMC, I would probably run a 16 pound recoil spring. . . but for just rare occasional use, I would run the stock setup. AND, I sure would never be shooting alot of 45 Super or 450 SMC anyway at over $1.00 per round.
The main reason 450 SMC exists is because Garey Hindman trademarked the name "45 Super". His late father actually was one of the main guys who helped Dean Grinnel develope the awesome "45 Super" cartridge. Garey's father customized 1911s to handle the Super. The USP 45 was the first production handgun which came from the factory ready, willing, and able to fire the 45 Super straight out of the box with no modifications. Anyone who markets ammo with the name "45 Super" on it must pay Garey for the right, and that is why DoubleTap sells 450 SMC instead.
The USP 45 is a BEAST, and is fine with running 45 Super even with it's stock 14 lb primary recoil spring, due to it's dual recoil-spring system. If you are running a 20 lb primary recoil spring, you are TOTALLY absolutely FINE with the 450 SMC cartridge. If I were shooting alot of 45 Super or 450 SMC, I would probably run a 16 pound recoil spring. . . but for just rare occasional use, I would run the stock setup. AND, I sure would never be shooting alot of 45 Super or 450 SMC anyway at over $1.00 per round.
The main reason 450 SMC exists is because Garey Hindman trademarked the name "45 Super". His late father actually was one of the main guys who helped Dean Grinnel develope the awesome "45 Super" cartridge. Garey's father customized 1911s to handle the Super. The USP 45 was the first production handgun which came from the factory ready, willing, and able to fire the 45 Super straight out of the box with no modifications. Anyone who markets ammo with the name "45 Super" on it must pay Garey for the right, and that is why DoubleTap sells 450 SMC instead.
