Hornady Handgun Hunter ammunition is built around a bullet as rough and rugged as the conditions and game demand. 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 a proprietary 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.