The early Norma 10mm Auto ammo threw a 200 grain JFP bullet at a smidge over 1,200 fps out of my early Colt Delta Elite. Warm!

The FBI 10mm loading: The FBI decided upon a 180 grain JHP at about 950 fps because that bullet weight at that velocity gave them the desired amount of penetration in their ballistic gelatin. The fact that it was much easier to shoot than full power 10mm ammo was a bonus to them.

Mr. Hall said that they could have gotten the same ballistic performance from the .45 ACP and it's 185 grain JHP but that they went with the 10mm instead because they wanted to adopt a cartridge that would make both the big bore and small bore/high cap crowds happy, a cartridge that didn't bring pre-concieved opinions with it, which baggage the .45 ACP and 9mm Parabellum had in spades!