300BlkTalk

Hi I was hoping for input. I’m having trouble getting my bolt to lock back on my 300black lantac enhanced bcg seekins adjustable gas block and a JP silent capture buffer h2 with green spring when using lighter spring will not cycle. The gas block is all the way open and even with sico omega can will not lock back. Anybody have any suggestions on what I’m missing. Also it is just with subs suppers are working
And it is a pistol length gas system

BustedGizmo wrote: ↑Sat Aug 10, 2019 1:39 pm Hi I was hoping for input. I’m having trouble getting my bolt to lock back on my 300black lantac enhanced bcg seekins adjustable gas block and a JP silent capture buffer h2 with green spring when using lighter spring will not cycle. The gas block is all the way open and even with sico omega can will not lock back. Anybody have any suggestions on what I’m missing. Also it is just with subs suppers are working
And it is a pistol length gas system

Hi there and welcome!

With those symptoms a couple of things come to mind.

What ammo are you using, store bought or handloaded?
-If handloads what powder, charge, coal, bullet, etc. are being used? (basically the entire round recipe plus velocity if you have it)


After ammo the only thing that comes to mind is that your gas block may not be properly aligned.
Maybe the barrel gas port (hole) and the gas block port (hole) are off just enough that your subs are having issue.


Ammo is easier to troubleshoot than taking apart and checking the gas block and barrel alignment so let us know all you can about the ammo

Usually you adjust gas with a gas block and not a H2 buffer at the same time. Try a standard buffer. It seems like you don't have enough gas to move that mass.

With an adjustable gas block you can use lightweight parts. No need to run a heavy buffer. Use the adjustable gas block to tune the cycling instead of the buffer.