Info I pulled off of the net..

5.7x28 ammo is a relatively small but very fast centerfire cartridge that was developed after NATO requests for a 9mm Luger replacement caliber. About a decade since that development, 5.7x28 is the caliber of choice for military and law enforcement in about 40 countries all over the world.

Published reports indicate that as factory loaded the 5.7x28mm drives a 32 grain bullet, load #SS190-AP (armor piercing), at a muzzle velocity (MV) of 2350 fps with 390 ft. lbs. of muzzle energy (ME). The 28 grain spitzer bullet, load #SS195LF-JHP, has a muzzle velocity of 2350 fps and muzzle energy of 290 ft.