I went back and forth on whether this would fit better in Rifles, Anmunition, or GunSmithing as it involves all three...
I assembled a .308 AR-10 this summer. I was finally able to get it out Shooting a couple months ago. With 7.62 NATO 147 gr ammo it runs perfect. With my handloads that are basically 168 FGGM copies it appears to be overgassed. I am shooting it suppressed the majority of the time and that is the plan. I sjot it again a couple weeks ago and it ran fine unsuppressed with the 168’s and also suppressed and unsuppressed with the 147 NATO ammo.
Last night I installed a JP adjustable gas block. I test fired a few rounds tonight. I closed the adjustment screw all the way down and then opened up one full turn as suggested in the installation instructions. I tried it with one round in the mag. Fired ejected and locked the bolt back. I screwed the adjustment screw in one half turn and tried again. Fired, ejected but bolt closed on an empty mag. Opened the screw 1/4 turn. Fired ejected and locked back on empty. I then tried it with two rounds in the mag and it worked as it should.
All seemed well well until I picked up the empty cases and saw ejector marks on three of them. It may be awhile until I can make it to the range for a real test fire so I figured I’d check with you guys to see if you and any experience with this. I have not seen the ejector swipe before installing the gas block. I know the case head swipe can be caused by high pressure and/or timing issues. I
I went with the adjustable gas block over changing buffer and spring weights as I figured it was a more ‘proper’ solution.
I assembled a .308 AR-10 this summer. I was finally able to get it out Shooting a couple months ago. With 7.62 NATO 147 gr ammo it runs perfect. With my handloads that are basically 168 FGGM copies it appears to be overgassed. I am shooting it suppressed the majority of the time and that is the plan. I sjot it again a couple weeks ago and it ran fine unsuppressed with the 168’s and also suppressed and unsuppressed with the 147 NATO ammo.
Last night I installed a JP adjustable gas block. I test fired a few rounds tonight. I closed the adjustment screw all the way down and then opened up one full turn as suggested in the installation instructions. I tried it with one round in the mag. Fired ejected and locked the bolt back. I screwed the adjustment screw in one half turn and tried again. Fired, ejected but bolt closed on an empty mag. Opened the screw 1/4 turn. Fired ejected and locked back on empty. I then tried it with two rounds in the mag and it worked as it should.
All seemed well well until I picked up the empty cases and saw ejector marks on three of them. It may be awhile until I can make it to the range for a real test fire so I figured I’d check with you guys to see if you and any experience with this. I have not seen the ejector swipe before installing the gas block. I know the case head swipe can be caused by high pressure and/or timing issues. I
I went with the adjustable gas block over changing buffer and spring weights as I figured it was a more ‘proper’ solution.