Hornady 90933 45 ACP +P 160 gr MonoFlex 20 Per

The MonoFlex handgun projectile is manufactured with a tough copper alloy that achieves deep penetration and 95% weight retention. Bullet expansion across a range of velocities is aided with an elastomer material added to the bullets open cavity. Upon impact, the elastomer compresses, then pushes out and causes the bullet to expand faster than a standard hollow point design.