Need schooling on adjustable gas blocks...

daved20319 · Mar 25, 2022

So, no big surprise, but my brand new PSA upper is over gassed. Already tried a Tubb's flat wire recoil spring and heavier buffer, that did the job for my 20" rifle length upper, but no joy on the PSA, it's a mid-length 16". I won't be running lots of different ammo in this upper, nor is it likely to ever get suppressed, I'm just looking to "correct" the ejection pattern, it's currently at 1:00 or so. Not looking to spend a ton, this is mostly just a range toy, not a "go to war" rifle, so something I can set and forget. Thanks, guys.

Dave

powermad · Mar 25, 2022

BRT gas drive will cure that.
Just select the one for the buffer and spring you want to use.

An A5 action will get you more buffer selections too.

On my 16" mid gas I run the A5 with an A5H2 buffer and Tubbs flat wire spring.
I'm using a BRT tube sized for that set up.
Before it was using an A5H4 buffer.

msgriff · Mar 25, 2022

The cheapest tunable gas system is a DIY version of the BRT Custom-Tune (no longer sold). It takes some basic shop skills, and would require the appropriate tooling (drill press, vise, numbered drill set, appropriate 10-32 tap, etc.). Material costs are under $1, but it does take time. Other than that, Aero AGB, usually under $60.

powermad · Mar 25, 2022

msgriff said:
The cheapest tunable gas system is a DIY version of the BRT Custom-Tune (no longer sold). It takes some basic shop skills, and would require the appropriate tooling (drill press, vise, numbered drill set, appropriate 10-32 tap, etc.). Material costs are under $1, but it does take time.

If I get another gassy barrel this is the route I'll take.
It'll probably cost more in ammo to tune than materials.

titsonritz · Mar 25, 2022

BRT is the cheap and easy way to go, RIFLESPEED is the new kid on the block with a great concept but will cost you more in work and/or money.

msgriff · Mar 25, 2022

powermad said:
If I get another gassy barrel this is the route I'll take.
It'll probably cost more in ammo to tune than materials.

The "cheat" is to use the recommended BRT EZ Tune size and reduce the diameter by one drill number size, e.g. EZ Tune 0.076" (#48) - use a #49 drill (0.073") for a gas port or Custom Tune equivalent.

powermad · Mar 25, 2022

The cheat is to get a barrel that doesn't have a gas port big enough to stub a cigar out in.
But it doesn't always work out that way.

arrowshooter · Mar 25, 2022

OP, so to your question Joe Bob's has a few options, as do most retailers, and it's pretty much up to you what you buy. I have a couple of the cheepies and some more expensive ones, and they are all "set it and forget it".