Question: what is the difference between 40 cal and 10mm?
Answer: 40 S&W is sparked by a small pistol primer, while the 10mm uses a large pistol primer. The larger and faster 10mm will give 624 foot-pounds of muzzle energy when sending a 180-grain bullet at 1,250 fps, while the . ... 40 S&W will give a slight advantage in the energy department over the .