Hornady 400421 HAP 10mm Auto .400 180 gr Hollow Point 500 Per Box/ 2 CaseModeled after the legendary XTP bullet design, HAP (Hornady Action Pistol) bullets are further refined into the perfect competition projectile. While XTP bullets use folds and a cannelure to aid in controlled expansion and terminal performance, Hornady has eliminated these from HAP bullets leaving only a sleek and balanced projectile with a protected nose that aids in consistent and reliable feeding in autos.