Lee 5.7x28 FN Factory Crimp Die crimps the bullet firmly in place. Tests demonstrate that even bullets which have no crimp groove will shoot more accurately. A firm crimp improves accuracy because pressure must build to a higher level before the bullet begins to move. This higher start pressure insures a more uniform pressure curve and less velocity variation.
Incorporates a collet to apply a rifle type crimp to the case. Makes these very difficult to crimp cartridges a delight to reload. Bullets do not need a crimp groove, as the collet is so powerful it will form one. Lee 5.7 x 28 FN Bottle Neck Factory Crimp Dies crimps the bullet firmly in place for the bottleneck cartridge.