Carrier & Carrier Key Sealant
This guide details the process of replacing bolt carrier group (BCG) key screws and applying sealant for a better gas seal. The video highlights that some manufacturers, like Five Seven Arms, use sealant on the carrier key to ensure a more efficient seal and retain screws. It also discusses potential causes of gas blow-by, such as uneven mating surfaces, and notes that while sealant helps, it may not always eliminate minor blow-by.












