Having fired both, and not referring to any charts about muzzle velocity, and ft. lbs., I would have to say the .400 C-B. I've shot relatively weak 150 gr.handloads out of a heavy 1911 style 400 pistol and the recoil was much greater than full power 180 gr. factory loads out of a (light) Model 20 Glock. Both rounds are near top of the list for (practically sized) automatics as far as I'm concerned.