An AR-15 bolt carrier group is a piece of a firearm that houses many key parts such as the firing pin, gas key, cam pin, extractor, and bolt. With all these pieces working together the BCG can grab and feed another round out of the detachable magazine chamber. During the extraction of a cartridge, the BCG works to absorb the force of the explosion by expanding gas in the carrier. Throughout this process, gas is tapped off from the barrel and sent into the cup inside of the gas key which creates an inertial force that sends the Bolt Carrier Group back into the buffer tube. This entire process helps to reduce recoil.
About this BCG: This BCG is made by the experts at Mercury Precision. It has a nitride finish to add to its durability and strength. It has been HPT and MPI tested to ensure that it is made with zero flaws. The full-auto profile of this BCG adds to its innovative design. Users will be able to feel the difference this BCG makes in their build.
Caliber Compatibility: .223 Rem, 5.56 NATO, .300 BLK, .350 Legend - This BCG is standard for the .223 Rem, 5.56 NATO, .300 Blackout, .350 LGND calibers, and is interchangeable between all 4 simultaneously. This includes .22 Nosler Chambered AR-15s and .223 Wylde rifles.
Finish: Nitride - Nitriding is a process during manufacturing that diffuses nitrogen into the steel to make a case-hardened surface for improved resistance and strength. A Nitrided BCG typically has a gloss black texture. Nitrided Bolt Carriers have increased resistance to heat, and corrosion.
Material: 9310 Alloy Steel - Bolt Head - 9310 Steel is a low alloy steel that is a mixture of nickel, chromium, and molybdenum. This steel is built to have high core hardness and high fatigue strength which make it the perfect steel to hold up in the harsh environments of the bolt head.
8620 Alloy Steel - Body - 8620 Steel is a carburized alloy steel meaning carbon was added to increase the hardness of the steel. 8620 is known for its high case toughness and high core toughness. Made mostly of nickel concentrate, this steel can easily withstand the firing stress of the BCG under operation.
Forward Assist Notches: This BCG comes with forward assist notches that allow the forward assist on the upper to contact the BCG, pushing it forward and locking the bolt into place. These forward assist notches can also help clear malfunctions in a speedy manner when the BCG becomes jammed.
Gas System: Direct Impingement - Direct impingement is the process of directing the gas created during the operation of a firearm through the barrel, gas block, gas tube, and eventually into the BCG again to cycle the action and prepare the firearm for another round.