Ok ,
I just finished getting my CAI FrankenInch back together - and I took about 2-2 1/2 inches off the barrel.
Prior to the rework , it would put most shots into a paper plate at 100 yards. 8 -10" groups , no matter who pressed the trigger , or what ammo.
Having put a new crown on the shorter barrel , as well as a US flash hider , and an Inch pattern gas block , I find myself wondering if I need to open the gas port up , as I don`t have enough pressure to cycle the action.
The gas plug is installed correctly , I`m finding carbon on the gas piston , gas piston moves freely , the ports are lined up , and I`m getting pressure signs on my brass/primers.
The regulator is presently set at "0" , which cycles the bolt far enough to reset the hammer, but not extract the spent case.
I know there`s a time/pressure/port size/barrel length relationship , just can`t recall what the port diameter should be on the 18" barrel .
Anyone have any thoughts ? It ran before , just wouldn`t group. Now, it puts everything into 2" with 47 year old eyes behind the sights , just won`t cycle enough.
Help ? Please
I just finished getting my CAI FrankenInch back together - and I took about 2-2 1/2 inches off the barrel.
Prior to the rework , it would put most shots into a paper plate at 100 yards. 8 -10" groups , no matter who pressed the trigger , or what ammo.
Having put a new crown on the shorter barrel , as well as a US flash hider , and an Inch pattern gas block , I find myself wondering if I need to open the gas port up , as I don`t have enough pressure to cycle the action.
The gas plug is installed correctly , I`m finding carbon on the gas piston , gas piston moves freely , the ports are lined up , and I`m getting pressure signs on my brass/primers.
The regulator is presently set at "0" , which cycles the bolt far enough to reset the hammer, but not extract the spent case.
I know there`s a time/pressure/port size/barrel length relationship , just can`t recall what the port diameter should be on the 18" barrel .
Anyone have any thoughts ? It ran before , just wouldn`t group. Now, it puts everything into 2" with 47 year old eyes behind the sights , just won`t cycle enough.
Help ? Please