Geissele 5.56mm Reliability Enhanced Bolt Carrier Group & Gas Key 05-2992 is a full-mass, full-auto rated M16/M4 bolt carrier group manufactured in Geissele's North Wales, PA facility. The carrier is machined from mil-spec 8620 steel and features a properly torqued and staked, chrome-lined, Nanoweapon-coated gas key.

This 5.56 BCG carries extended upper rails that provide much greater stability and dramatically increase feeding reliability compared to a standard carrier. That extra rail contact matters most in a dirty or high-round-count gun, where a standard carrier starts to wobble slightly inside the receiver as tolerances open up over time. This Geissele Bolt Carrier group is coated in Nanoweapon for maximum corrosion and wear resistance, a coating developed originally by Picatinny Arsenal and refined by Geissele's engineers over three years of joint development work.

At a surface hardness of 82 HRC, this Geissele enhanced BCG rejects carbon buildup and makes cleaning noticeably easier, while also letting the weapon run reliably with less lubrication than a standard carrier requires.

Key Features:

• Full-mass, full-auto rated M16/M4 bolt carrier group
• Machined from mil-spec 8620 steel
• Chrome-lined, properly torqued and staked gas key
• Extended upper rails for stability and feeding reliability
• Nanoweapon coating, 82 HRC surface hardness
• Rejects carbon fouling, easier cleaning
• Reduced lubrication requirement
• Manufactured in Geissele's North Wales, PA facility

This Geissele reliability enhanced bolt carrier group upgrades one of the most failure-prone parts of an AR-15 without requiring a full rebuild.