Wilson Combat .223/5.56/300 BLK Low Mass Profile Bolt Carrier Group Polished NiB

Wilson Combat .223/5.56/300 BLK Low Mass Profile Bolt Carrier Group Polished NiBLow-Mass bolt carrier groups are a perfect choice for sporting or competition rifles tuned for ultimate recoil control and faster follow-up shots. Because of their light weight, Low-Mass bolt carrier groups unlock and cycle faster and should be used in conjunction with an adjustable gas block to fine-tune your action pressure and cyclic rate.Our bolt is precision machined from aerospace-grade 9310 tool steel, shot peened for increased strength, and includes a tool steel extractor and ejector, an appropriate extractor spring, and is MPI (Magnetic Particle Inspected) and randomly batch HPT (High Pressure Tested).The extractor is 4140 gun quality, annealed, cold-drawn steel per the Mil-Spec.The 8620 steel carrier includes a properly machined Mil-Spec gas key that is completely Nickel Boron plated for the ultimate in smooth operation and easy cleanup. It is secured to the carrier via Grade 8 fasteners and properly staked in our shop during final inspection.These precisely machined, finished, and hardened parts will ensure long-term proper gas system functioning and reliability.All experienced AR shooters know that the best spare parts kit for an AR-15 rifle is a spare complete bolt carrier assembly!NOTE- The only difference between "semi-auto" and "full-auto" carriers is the carrier weight and external profile. The "full-auto" carrier is slightly heavier to provide more mass and lower cyclic rate that can benefit carbine length and shorter gas systems, short-barreled/suppressed rifles, and machine guns. The "semi-auto" carrier is slightly lighter to provide the least amount of recoil impulse for rifle-length gas systems, and its design makes reinstalling the firing pin easier after cleaning.Both carrier types are considered completely interchangeable, and there are no restrictions on the ownership of a "full auto" carrier group in a semi-automatic rifle.Features Polished Nickel Boron Plated for easy cleanup and less lubrication Bolt material is aerospace-grade 9310 MPI inspected Mil-Spec parts ensure a long service life Machined ejector and extractor per MIL specs Weight: 9.08 oz Drop in fit for any quality 5.56 case head-based AR rifle (.223/5.56 NATO, .300 Blackout, .204 Ruger, 300 HAM'R or 7.62X40 WT)Why Nickel Boron is a Superior Choice for AR Bolt Carrier Groups Outperforms hard chrome and nickel-phosphorous (hardness/wear resistance Withstands high temperatures and is easy to clean High hardness (Rockwell 70 C +) Greater abrasion and wear resistance over time Low coefficient of friction requires less lubrication No hydrogen embrittlement