The Lee 25/20 Winchester Factory Crimp Die provides a superior crimp that holds the bullet firmly in place, more effectively than any other tool. Tests have shown that even bullets without a crimp groove benefit from this die, with improvements in accuracy. A firm crimp enhances accuracy by requiring higher-pressure before the bullet begins to move. This higher starting pressure ensures a more uniform pressure curve, leading to less velocity variation and more consistent performance. Ideal for reloaders seeking precision, the Lee Factory Crimp Die helps to optimize the reliability and consistency of your ammunition.