11-24-2013, 09:13 PM
Yes, from the shoulder of the barrel where it steps down to the gas block journal, to the gas port center is typically .250". Gas block journal lengths differ depending on what type of gas block will be used, and the two main divergences here are:
* Standard FSB (military-type or similar using taper or straight pins)
* Low profile or non integral front sight gas block
Either way, most barrels will have a 1.900" journal length, from the shoulder to where the barrel profile steps down. A .750" gas block journal usually steps to a .725" barrel fore end, until getting near the muzzle.
The gas system lengths I posted earlier are measurements from the face of the barrel extension flange (some call it a torque ring).
* Standard FSB (military-type or similar using taper or straight pins)
* Low profile or non integral front sight gas block
Either way, most barrels will have a 1.900" journal length, from the shoulder to where the barrel profile steps down. A .750" gas block journal usually steps to a .725" barrel fore end, until getting near the muzzle.
The gas system lengths I posted earlier are measurements from the face of the barrel extension flange (some call it a torque ring).