AFTE Store - Heckler & Koch – Model HK4 Pistol

This is a description of the of the Heckler & Koch, Model HK4 pistol which can be converted to fire both the 380 A.C.P. and 22 Long Rifle caliber cartridge. This design feature produces unusual class characteristics on both the 380 A.C.P. and the .22 Long Rifle caliber cartridge cases fired in this pistol.