The 7.5 FK caliber ammunition is a proprietary caliber designed and produced by FK BRNO Engineering s.r.o. This caliber was designed specifically to bridge the gap between standard handgun and carbine rifle calibers in terms of power, efficiency, range, and accuracy. While at the same time it’s compact enough to be used in a standard size automatic pistol with a 5-inch or 6-inch barrel, and when used in pistols with FK BRNO’s patented recoil attenuating system, it has recoil comparable with calibers with less than half the kinetic energy.