Federal has introduced a new caliber, the 30 Super Carry. It looks like a .31 caliber, 100-120 grain bullet at between 1000 and 1250 FPS. The benefits are increased mag capacity, stopping power similar to 9mm, and less blast/recoil than 9mm. Federal indicates they designed the round from the ground up for use in the mini 9mm sized guns, and to have better ballistics than .380. They also say that because of the reduced recoil impulse, the recoil spring is lighter, resulting in easier slide racking.
Wonder if this one will catch on, or if it's destined for a Forgotten Weapons episode...