7.5 FK® calibre ammunition is a proprietary calibre designed and produced by FK Brno. This calibre was designed specifically to bridge the gap between standard handgun and carbine rifle calibres in terms of power, efficency, range, and accuracy. While at the same time its compact enough to be used in a standard size automatic pistol with a 5- or 6-inch barrel, and when used in pistols with FK BRNO’s patented recoil attenuating system, it has recoil comparable with calibres with less than half the kinetic energy. The following are calculations of conventional ballistic data for the 7.5 FK® cartridge.

F9: All copper monolithic wide meplat flat nose. This bullet is designed to create a wide and very deep permanent wound channel in addition to a very high dynamic shock effect. Accurate and effective for defence and medium game hunting up to 300 lbs to 100 yards, and dangerous game up to 500 lbs to 50 yards.

S95: Jacketed Hollow point made by Sierra bullets exclusively for FKB, it is designed to explode and shatter on impact. This bullet makes huge, but shallower wound channels than the other versions. Accurate and effective for defence and medium game hunting up to 100 lbs at 100 yards.

F5: All copper, monolithic nose discarding hollow point. The nose is designed to break off on impact, leaving a jagged 7mm meplat to create a large deep penetrating wound channel and a High Terminal Effect. Accurate and effective for defence and medium game hunting up to 200 lbs to 100 yards.

F7: All copper, monolithic spoon tip. This bullet is designed to tumble after the initial impact and penetration, creating a very large eliptical and deep penetrating wound channel. Accurate and effective for tactical use up to 150 yards and dangerous game hunting up to 500 lbs to 50 yards.


FK BRNO® has developed and patented the DSI ,an alternative computational system for measuring the efficacy of handgun cartridges. This methods measures the probability of instant incapacitation when compared to other calibres. The development was based extensive field testing and recent and historic war casualty data. It is calculated as follows:

Dynamic Shock Index [DSI] = Meplat Diameter x impact velocity – (1500-impact velocity) x sectional density

CARTRIDGE MAKE MEPLAT Velocity fps @ 1m SD DSI @ 1m Velocity fps @ 90m DSI @ 90m
7.5 FK F9 FKB 0.236 1920 0.160 72.5 1450 52.8
44 MAG 240 gr JHP XT 0.255 1280 0.185 50 1030 26.4
7.5 FK F5/S95 FKB 0.157 2000 0.150 47.1 1610 37.9
357 Mag 125gr JHP MT 0.248 1378 0.140 43.6 1110 25
10 MM 180gr JHP BB 0.236 1250 0.160 37.8 1050 22.6
45ACP 185gr +P JHP MT 0.255 1148 0.139 30.6 973 15.8
9 MM 124gr +P JHP GD 0.208 1262 0.140 29.8 1054 17.7
9 MM 135gr +P JHP CD 0.157 1241 0.153 18.8 1050 14.4


The 7,5 FK SS