1875 FPS is typically the speed listed when fired from the FN Five-seveN pistol. It should be around 2400 fps or so from a rifle. It won't ever run with a .223 Rem, so no advantge in a carbine as far as ballistic performance. It is really good at what it was designed to do though, provided interchangeble ammo between rifle and handgun for LE/Military. The handgun fully loaded (20 + 1 rounds) is extremely light (think empty Glock 22 weight).

Next time I have my Five-seveN out I will try to chrono it. It is what stays loaded in the GunVault in the night stand. My wife loves the light weight and very low recoil.