Deaf Smith, you are comparing a RIFLE cartridge to a PISTOL cartridge. The powder in the carbine round burns much slower and is not suited to a short barrel like a pistol has. Out of a 6" barrel a typical .30 carbine round is lucky to do 1300fps because most of that powder burn time is wasted in muzzle blast since a carbine rifle has about 18" of barrel and the powder is intended for the burn time a long barrel offers which gives an average bullet speed of up to 2000fps. The 7.62x25 is made specifically for a short barrel gun and has a faster burning powder to maximize the pressure build to drive the bullet to its intended velocity, which in this case for a 4.72" barrel is about 1650fps with much less muzzle blast. The 7.62x25 round originally was intended for a Russian designed SMG which has a 120mm barrel as does the CZ52. In fact these two guns were both made to share the same round so that a Russian soldier did not have to carry two different kinds of ammo. The KGB liked the pistol since it was designed to not hang on clothing yet put a hole in whoever they shot regardless of how much heavy clothing they wore. I reload (as do many here) so I do take burn time into consideration as well as other factors, like chamber pressure, size of the powder charge, burn rate and bullet weight. Ok, I'll step off the soapbox now.