Wilson Combat Bullet Proof® .308 AR Firing Pin The firing pin of a .308 AR rifle is under intense pressure and factory steel and titanium units are often subject to breakage and excessive tip erosion or wear-especially with high pressure cartridges and higher round count guns. Since Wilson Combat’s high performance rifles deserve the highest performing parts they designed a Bullet Proof® firing pin machined from virtually unbreakable S-7 tool steel that will drop in any DPMS .308 compatible bolt. This standard dimension firing pin is guaranteed to never break or fail and will enhance the reliability of  any DPMS pattern .308 rifle and all other compatible calibers that use a .308 bolt assembly. Drop-in, Mil-spec “DPMS/SR-25” bolt dimensions (not compatible with Armalite® AR-10®) Hard chrome finished for corrosion protection and easy cleanup Machined from virtually unbreakable S-7 tool steel