I think the question refers to the "kinetic energy" of the firearm, whether pistol (semi-auto) or a revolver, under recoil.
Considering only the type of "action", I would say that .45acp semi auto pistol would have less kinetic energy due to the slide and the recoil spring absorbing a substantial portion of the recoil impulse, compared to a .45acp revolver. However, we should factor in the weight of the handgun. A polymer framed Glock 21 (.45acp) weighs approximately half of a steel N-frame (large) S&W Model 25 in 45acp. I would say the recoil impulse would be similar, or close.
Now if we compare a steel 1911 45acp and an N-frame steel revolver, with the revolver being heavier but the 1911 has a recoil absorbing slide, I'd say somebody who has shot both please chime in. Which recoils harder?
I own both. The revolver kicks less. - dan


















































