Product Description The Wilson Combat TRBCA Bolt Carrier Assembly is a drop-in bolt carrier solution for quality AR-platform rifles built around the 5.56 case head. It is precision machined from Carpenter 158 steel and shot peened for increased strength, with a tool steel extractor and ejector, a correctly matched extractor spring, and randomly batch high-pressure testing (HPT) for added confidence in hard use. This full-auto profile carrier is slightly heavier than a semi-auto carrier to add mass and help reduce cyclic rate, which can be beneficial for carbine-length and shorter gas systems, short-barreled or suppressed rifles, and machine guns. Both full-auto and semi-auto carrier types are interchangeable. Product Highlights Drop-in fit for AR rifles using the 5.56 case head Carpenter 158 construction with shot-peened processing for increased strength Includes tool steel extractor and ejector with appropriate extractor spring Randomly batch HPT (High Pressure Tested) for added reliability assurance Full-auto carrier profile adds mass to help lower cyclic rate for short and suppressed gas systems Specs Product Type: Bolt Carrier Assembly Platform Compatibility: AR rifles based on the 5.56 case head Caliber: 5.56x45mm NATO Carrier Type: Full Auto Material: Carpenter 158 steel Finish/Color: Black Parkerized Testing: Randomly batch HPT (High Pressure Tested) MPN: TRBCA UPC: 874218067922 Brand: Wilson Combat Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the products manufacturer.