General Info: An AR-15 9mm 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. For 9mm bolt carriers, the bolt head is flat and is critical in creating a seal on the blow-back design of AR-15 9mm Pistol Caliber Carbines.
About this BCG: This side-charging BCG is a premium component you should add to your next 9mm build. This BCG is made from durable material with a finish that improves lubricity, corrosion resistance, and carbon resistance. It takes the classic BCG design and elevates it.
Caliber Compatibility: 9mm Luger (9x19) - This BCG is designed for the 9mm caliber. The most common pistol cartridge in the United States.
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: 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.
Gas System: Direct Blow Black - Pistol Caliber Carbine AR-15 rifles do not tap off-gas from the barrel and work in a direct blowback configuration, therefore the gas key is installed to index alongside the charging handle to allow manual operation of the platform.
