JMAC Customs GBC-13 Front Sight Gas Block Combo

  • Sale
  • $ 109.95

GBC-13 is a reproduction of the East German 74nk Front Sight Gas Block Combo.  It is perfect for pistol, rifle, and SBR builds because it lightens up the front end of your gun, as well as gives it a custom look. There are 2 options available: with and without detent hole. Please note that if you are using them on a pistol or SBR you will want the detent hole so you can secure your muzzle devices in place with a spring and detent.


  • Fits common 0.591" gas block barrel journals 
  • Has 90° gas port and is a direct replacement for most 90° gas blocks (will work on 45° gas ports with minor gunsmithing)
  • Uses standard front sight windage drum and pin
  • Has built in cleaning rod holder
  • Cast in the US using wax casting techniques similar to the modern Russian barrel components
  • Machined in the US
  • 4140 heat treated to Rockwell 32C
  • Black nitrided in the US

DISCLAIMER: These come stripped. They do not include the windage drum, front sight post, detent, spring, or barrel component pins.