Handgun Hunter deep penetration makes it a great round for your backup handgun. Each load features Hornady’s MonoFlex bullet, combined with premium cases, primers and powders. Harder and tougher than solid copper, the copper alloy of the MonoFlex bullet doesn’t separate, achieving deep penetration. A unique elastomer material is added to the bullet’s open cavity. It compresses upon impact, then pushes out, causing the bullet to expand quicker than a standard hollow point.