As better armor, specifically face hardened armor, became more widely used in surface combatant construction, the penetration capability of existing naval shells was significantly reduced. To countert his new armor type, shells began to be fitted with an armor piercing cap. The chief function of the cap is to enable the head of the shell to survive the shock of the initial impact without rupturing or breaking up. When a capped shell strikes a face hardened plate, the front portion of the cap flattens out absorbing the shock of impact and protects the head. As the rest of the shell is still in motion, due to inertia, the head of the shell can easily pass through the arrested cap and come in contact with the armor plate. As the armor has already been stressed by the impact of the shell, and as the head of the shell is still intact, the maximum amount of kinetic energy is transferred to the weakened structure. With an armor piercing cap, a shell of the same mass and impact velocity will penetrate up to 25% to 33% more armor than a shell without a cap. Gunnery Standards in the Admiralty Trilogy Games Armor Piercing Cap Optical Range Finder BT Back to The Naval Sitrep #12 Table of Contents Back to Naval Sitrep List of Issues Back to MagWeb Master Magazine List © Copyright 1997 by Larry Bond and Clash of Arms. This article appears in MagWeb (Magazine Web) on the Internet World Wide Web. Other military history articles and gaming articles are available at http://www.magweb.com