Hey guys looking for AR advice, so I cut my 6.5 Grendel's Lothar Walter barrel down to 18 inches (to be legal for team safari last year), it has rifle length gas, I've altered the pressure. It won't cycle unsuppressed even after John Paul told me at the match to try the lightest spring for the silent capture buffer spring, but it still doesn't work. Now with my thunderbeast ultra 7 on it, it will cycle but it's not pretty. I got an slr adjustable block and I've got it tuned to eject about right at 4, but man the brass is beyond dirty like caked on so I think it's overgassed not sure. I've tried both the light and heavy jp buffers and springs, have both. I'm shooting factory hornadys (til I figure this out), running a prs stock and a vltor upper/hand guard, kind of a pita taking off and on trying to figure this out before I just rebarrel it. I've been told to drill the gas port larger among other suggestions, and also something about plugging the hole and re drilling location? Not sure what that would cost (sounds sketchy) or if I should just re barrel. It's an accurate barrel so I'd like to run it suppressed but something's not right with the brass, my blackout brass comes out way cleaner with a can and I'm running pistol powder there. Any advice appreciated thks.
Gunsmithing 6.5 Grendel problem
- Thread starter bladehound86
- Start date
Doesn't take long to gunk up and start sticking a little
Cant comment on the actual issues but my one note of observation- that looks like your chamber is all oily to me, the only time my brass has had those wavy smears is after cleaning that I didnt wipe the chamber dry on.
I run a JP 18" rifle gas grendel and it is picky on which powder it works best with. I am currently running 123 scenars with H4895 generates enough gas to run the JP full mass carrier and the second from the heaviest spring in the SCS... I don't shoot suppressed so I cant offer any help there. Now if I could just get my mags to reliable feed when loaded to mid and full capacity.
If you roll your own then you could try Vihtavouri powder to get a little cleaner. My 5.56 brass comes out nasty when suppressed, but not that nasty. I doubt you are over gassed if ejection is at 4 o'clock.
Ok, could be on that batch, I think I covered a clean chamber but I'll shoot some more tomorrow after cleaning. I already have some 4895, TAC, and AR Comp and some 123 hornady ssts I could try, haven't set up the dies yet.
That would be awesome , I just assumed there was one since all my other calibers run thru can cleaner. I'll check ejection and grouping again once rain clears up. Cleaned gun last night
call lothar and ask what size the gas port is and open it up 1 step. when I ordered my last custom barrel the gas port is opened just enough to cycle with a standard gas block. adjustable gas blocks need a bit more gas to cycle the action same with heavier buffers.
lothar should even be able to tell you what size it needs to be based on reduced barrel length and current setup.
lothar should even be able to tell you what size it needs to be based on reduced barrel length and current setup.
That looks pretty much like the brass out of my semi-autos when running suppressed. I had a piston gun that would soot much worse, the entire piece of brass case head and all would come out solid black.
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