EXPERIENCE OPTIMAL RELIABILITY AND PERFORMANCE IN YOUR RIFLE WHEN YOU CHOOSE THE WILSON COMBAT BOLT CARRIER ASSEMBLY FOR 5.56 NATO. THIS ROBUST DESIGN ENSURES RUGGED DEPENDABILITY, REGARDLESS OF CONDITIONS. THE BOLT CARRIER ASSEMBLY FEATURES A BLICK NITRIDE COATING AND IS PRECISION MACHINED FROM AEROSPACE GRADE 9310 TOOL STEEL, MAKING IT INCREDIBLY TOUGH. THE HARDENED STEEL 8620 CARRIER ALSO FEATURES ASSIST CUTS FOR ADDED RELIABILITY.