An AR-15 .45 ACP 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 .45 ACP bolt carriers, the bolt head is flat and is critical in creating a seal on the blow-back design of AR-15 .45 ACP Pistol Caliber Carbines.
About this BCG: The Recoil Technologies .45 ACP Bolt Carrier Group is a high-mass PCC bolt carrier that works with Glock and Colt magazines. The high-mass improves the delay in blowback operation to ensure chamber pressure drops safely during operation. The carrier body is made from 8620 Steel and utilizes a standard PCC firing pin and AR-15 extractor.
Caliber Compatability: .45 ACP - This BCG is designed for .45 ACP. A heavy hitting pistol cartridge originally design for the self loading 1911 handgun.
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 from 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 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.