FN Herstal stepped way out of the civilian handgun production box when brought to market the 5.7x28mm round for their Five-seveN MK2.
The FN Five-seven makes a good target pistol that doubles as a defensive weapon. The ballistics might not be as battle-proven as 9mm para or .45 ACP, but its light recoil and capacious magazine capacity make the FN Five-seven a serious combat pistol.
The Excel Arms Accelerator is a sweet little rifle that comes chambered in either .22 WMR or 5.7x28mm. MSRP runs from $512 to $937 depending on what features you get with it.