More expansion however, does not always mean the bullet will set up with a wider frontal diameter. Sometimes, high velocity causes a bullet to peel back more, creating a smaller frontal diameter. This can make the bullet penetrate deeper. It all depends on bullet construction. Both Black Hills and DoubleTap ammunition load this bullet for the .40 S&W, and like all the TAC-XP bullets I've tested, it performs very well. The variance between the loads is due to the velocity difference.