Considering getting a pistol. Have decided on a semi-auto, but cannot decide on which would be better for personal protection. 40 S&W or 45ACP. Would love your real world feedback on which caliber has the best characteristics when relationship to stopping power, recoil, availability, etc. Would love your opinions to help me make up my mind.....I have shot a friends 40 but haven't shot a 45 yet. I am not sure what kind of rounds he had in the 40 but he said they were pretty stout. The recoil was noticable but not too bad. This may also be used by my wife and daughter if the need would ever arise.