IME one of the biggest issues that ARs deal with is over-gassing. There’s a couple of solutions that use like donuts on the extractor and heavier buffers / buffer springs. But those aren’t really solutions, they’re just band-aids that mask the problem of the BCG getting too much gas.

Adjustable gas blocks are a solution, but are pricey and overbuilt for the solution that’s needed, and can pose their own problems if they’re meant to replace a pinned gas block and the barrel isn’t dimpled.

I had a similar problem recently in one of my guns. After switching to a new ammo for practice I had an AR that began ejecting at 1 o’clock.

I contacted Black River Tactical about one of their ported has tubes. BRT’s gas tubes are ported, so you can meter the exact amount of gas you need without changing gas blocks, using only a single punch, and for only $40.

The first tube I ordered still wasn’t ported small enough and I emailed them asking for help. BRT actually went and bought a box of the ammo I’m using and tested gas tubes until they found exactly what I need and mailed it out to me.

I’m now ejecting at exactly 3 o’clock. Simple solution for only $40.

https://imgur.com/a/HErVsRY

Blue, have you ever tried an adjustable gas key? About the same price as the that gas tube. I haven't tried one but they look interesting.

RCA adjustable gas key

Sun Devil gas key

They used to make some bushings as well but the gas tube sounds like a better option.

That looks like a good way to get it dialed in.



Me personally, I don't mind the extra gas. It gives me confidence in the weapon during the dead of winter. I like to know it will function when the gun, lube, and ammo, are saturated in sub-zero cold. Mine are all factory gas, and milspec triggers.

Thanks for the clue, Blue.

Sounds fine except for the potential trial & error part.

Given the various types & pressure of ammo & handloads, combined with the variables of the gas port diameter variation on a given length, not sure they will be able to very accurately predict how to relieve the tube pressure for a mass commercial enterprise.

MM

They can get pretty close. They’ve started doing a lot of testing and are putting out their own barrels now.

If nothing else, you can just get it ported comparably to what BCM and such are doing and know that you’ll be pretty good with a wide variety of ammo.

Yeah, BCM seems to get it right.............I have one of their uppers with mid-gas, non-adjustable GB & it shoots & handles everything from low pressure 223 - full blown mil-5.56 absolutely 100%. Even steel case junk.

Ditto for a Sig factory upper & most recently, a PSA 14.5" mid-gas gun as well................just perfect.

On all my builds, mainly just to make life easy, given the mix of parts, etc, I've just decided to use an adjustable GB even at the added cost. The cheaper ones from Seekins or ODIN are not quite as nice as SLR's but they work just fine, IMO. The key is to actually adjust them from time to time & even clean them too, (God forbid).

MM

I'd not hear of that. Thanks for posting.

For guns that MUST go bang, I like the extra mass of either a heavier BCG, buffer, or both. The additional mass does better mashing through accumulated crud and contributes to increased reliability. You do pay a noticeable penalty in increased recoil, so there's that to factor in to the equation. I'm getting barrels chambered from Compass Lake Engineering now, and they will drill any gas port diameter I ask for. In fact, on my last barrel I told them what ammo I was going to run and what weight BCG and buffer. They drilled a port we thought would be too small, assembled the barrel into an upper and test fired it. They went up one size and tried again and the bolt just locked back. We went one size larger than that to guarantee reliable function when dirty (I shoot suppressed almost exclusively, and the guns get dirty fast).

I've had similar experience with PSA gas for their 16" mid lengths, and a 10.5" shorty.

No I haven’t. I know some 3Gun guys tried them and seemed to like them. But if I installed that I don’t have a tool to restake it.

Yeah, it’s good to find a happy medium. This gun now has a VLTOR A5H3 in it. All my guns have more spring and buffer than the standard carbine setup.