The redhawk might be a little stronger, the super redhawk stronger yet, not sure if they make the Super in .45 colt. the redhawk is a lot better if you want to scope it and is heavier which will make it recoil less.
OTOH, the blackhawk is plenty strong for anything you would want to use it for, is lighter, less expensive, has more barrel length options than the redhawk. Oh, and its much better looking too.
