Get the conversion with 3 lands of rifling. The 3 land bores have been relined and will shoot a standard 50 caliber bullet, as the other is too large to shoot most cast bullets you would shoot. I have shot everything from gophers to deer with this 50-70 conversion and 5744 powder with a 300 grain gas check bullet and it won't beat you up. It will still completely penetrate everything you will shoot with it...

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