Hello,  need some troubleshooting -Also posted in AR15 general topics

Finally got out to shoot my new 6mm ARC build

First test was to adjust the Seekins adjustable gas block.

I followed direction from Seekins:  start with adjustment screw 1 turn off all the way in.  Shoot 1 round only in magazine.  Repeat until rifle will lock back on empty magazine…..

1st shot didn’t eject
Adjusted 1/2 turn

2nd, 3rd, 4th and 5th wouldn’t eject each with additional 1/2 turn.

6th through 12 ejected but still not enough to lock back……ran out of adjustment.

I’m running a rifle length buffer tube, spring and rifle buffer 5.4 oz

Proof research 18” barrel with rifle +1 gas tube

Shooting Hornady factory 108 ELD match

What to try next? Lighter buffer?

are you sure the gas port in the barrel and on the gas block are aligned?

Good question. When I get home I’ll have to check that

I've not run a rifle buffer system before but I believe you should try a lighter one.

EDIT: I see that's a standard weight. I'd make sure the gas block is properly aligned and double check the gas tube orientation in the gas block (yes I've managed to make that mistake once).

Pull the pin and dump all the weights and try it empty.  If it won't lock back on an empty buffer you will have to take a look at the port.  If it does lock back, get some aluminum weights and tune it from there, mixing with the steel weights you already have, they are cheap.

Rifle length with +1” gas port is usually for 18” barrels with a suppressor.   If the gas block and gas port are aligned correctly sounds like your gun is under gassed.  If you take off the gas block be sure to measure the gas port.   Depending on the gas port size might help to determine the best course of action, lighter buffer or larger gas port.

Rogerthat

Probably going to work on it in the morning as I have to fix my lawnmower.  Lol

I have some buffers laying around in spare parts

I should have brought them and tested that but I’m going to check the gas block port alignment first.