JMac Customs GBC-13 Adjustable Gas Block Combo with Detent

Jmac Customs GBC-13 Adjustable Gas Block Combo Jmac Customs GBC-13 Gas Block Combo Durable 4140 Steel Black Nitride Finish Heat Treated East German 74nk Gas Block Replica GBC-13 Adjustable Gas Block Combo with Detent - JMac Customs. Durable 4140 steel gas block combo with a black nitride finish. High-quality replica of the East German 74nk gas block, designed to enhance AK builds with a lightweight yet durable construction. Works with 0.591" barrel journals, fits 90° gas ports.