Personally, I cannot percieve and appreciable difference in recoil from non-ported 10mm, .400cb, and 45acp+p. I have heard people say that ANY pistol can be learned to shoot rapidly if you practice. However, personally I think if you really want very rapid double-taps, go with a 9mm or comped gun. As between 45 and 400cb, I say go for the corbon - won't be much different from a +P (yes, it's more than a non-+P round, though).