{"product_id":"fz-m16-m4-bolt-carrier-group","title":"FailZero M16\/M4 Bolt Carrier Group – AR-15\/M16 Platform","description":"\u003cp\u003eThe FailZero M16\/M4 Bolt Carrier Group is a full-auto profile replacement BCG designed for AR-15 and M16 pattern rifles. Engineered to reduce friction and extend service intervals, this carrier group features FailZero's proprietary nickel boron coating applied to all critical wear surfaces. The coating provides permanent dry lubrication that won't cook off under sustained fire, making this BCG well-suited for high-round-count training, competitive shooting, or duty use where reliability under stress is non-negotiable.\u003c\/p\u003e\u003cp\u003eMachined from mil-spec 8620\/9310 steel with a nickel boron finish, the FailZero BCG requires minimal lubrication and simplifies field cleaning—carbon and fouling wipe away with significantly less effort than traditional phosphate carriers. Installation is drop-in for any mil-spec AR-15 or M16 upper receiver. The M16 profile includes a full-auto sear engagement surface, though it functions identically to a standard BCG in semi-automatic lowers.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Type:\u003c\/strong\u003e Bolt Carrier Group (Full-Auto Profile)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompatible Firearms:\u003c\/strong\u003e AR-15, M16, M4 (Mil-Spec)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e 8620\/9310 Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinish:\u003c\/strong\u003e Nickel Boron Coating\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstallation:\u003c\/strong\u003e Drop-In\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncludes:\u003c\/strong\u003e Assembled Bolt Carrier Group (Carrier, Bolt, Cam Pin, Firing Pin, Retaining Pin)\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"FailZero","offers":[{"title":"Default Title","offer_id":47937969357055,"sku":"FZ-M164-01-SAH","price":171.95,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0729\/0434\/3807\/files\/1260838.jpg?v=1766499884","url":"https:\/\/doublestackstore.com\/products\/fz-m16-m4-bolt-carrier-group","provider":"Double Stack Store","version":"1.0","type":"link"}