To the point. Most agencies chose the 9mm because there is not a lot of difference between the outcomes of shootings with a 45ACP, a 40 or a 9mm. Given the best bullets to be had, at their maximum velocities, all things considered they are all about the same speed and all penetrate about as deep and all do a similar amount of damage. This is not me making this up, it’s common knowledge. When I say all things considered, recoil, your ability to shoot the gun, accuracy to hit the right spot, ability to shoot fast and more than once accurately...all things considering all people who might use the gun. The other part Glockduffus aside, the 9mm if it penetrates 13 inches is going to produce about the same damage as a 45 that penetrates 13 inches. Now I can see the 9mm and 105 howitzer will be markedly different but .35 and .45 just ain’t. Jeff Cooper was just wrong.
