Please bear with me on this one but it's the only data I could come up with. From The Stopping Power Home Page (Marshall); 41 magnum Silvertip, 53 shootings, 89% "one shot stops". 45 ACP Federal Hydra-Shok, 71 shootings, 94% "one shot stops". There's newer 41 magnum loads on the market (Cor-Bon) and newer 45 ACP loads but no data as yet. Difficult question actually because normally a 41 maggie isn't used for human self-defense. Best Regards, J. Parker