The gas hole is definitely too small. I still need to decide what to do as far as the drill bit, but I'll be widening that.

I would at least start out with a #43 (.089") bit and work up to a #42 (.0935") if you need to.

Or if you don't want to mess with doing that you could just open it up to .098" or so and get a BRT gas drive for it.
Just select what buffer and spring you are using from the drop downs and get a gas tube sized for that.
But I wouldn't, I'd just get a couple of bits and work up.

A dimple jig for the gas block is pretty cheap and makes messing with that easier if you have it on and off.
I think the KVP one I have was $25.

I have a set of #43 drills on the way.

That BRT gas drive system intrigues me, but it doesn't come tuned for a 24" barrel, at least that I've seen yet. I'm not done looking though. I found their site and there's a configurable option that would meet my needs.

0.089" = ~2.26mm. I am really quite tempted to drill out to 2.5mm and install the adjustable gas block, simply because it's the most field-expedient means of getting the gun fully operational.

If going from over-sized the BRT tube is a solid, easy fix, good for over 5,000 rounds on a suppressed 10.5"
No parts to fiddle with to keep it working.

I had a Faxon barrel that had a huge gas port.
Cycled hard with an A5H2 buffer and Law folder adapter, which was another 2 oz.
Got a BRT tube sized accordingly and it smoothed it out.
Got it sized for full power ammo.
Tested some steel case and it choked.
Runs 5.56 like a champ.

Sold it to a buddy who of course bought steel cased ammo after being told about it.
I made a spacer for the extension and gave him a carbine buffer and spring to try out.

I've looked at both options and they cost about the same. I'm going to first try chasing the hole out with a drill and go from there.

Well, BA responded to my query about the gas hole. They drilled it at 0.086". Now wonder I'm having issues.

I ended up buying a gas block dimpling jig from SLR Rifle Works for $35 last night. I also have the aforementioned #43 bits waiting at the PO box.

I also replaced the barrel with that $300 Criterion of the same length. While I'm a little annoyed at the profile ( instead of staying at over 0.90" it's what I've seen as a a service rifle profile - it drops to 0.80" after the gas block journal) I'm okay with it because I know the gas system is good to go. I tested the gas port with my pin gage and it fits wonderfully. It's also dimpled so there's no question the block is lined up (no ghetto-ass tricks like dropping spaghetti in the barrel).

I'm going to enlarge the hole on the BA and dimple it, and I'm going to be building another rifle with a PSA kit I picked up last night, and I might even Ceracoat it if I can figure out a way to bake it.

I drilled it out over Thanksgiving break. Dunno how well it'll shoot, but I can say the gage pin fits like a glove now.

The parts to finish the new upper (minus the dimple jig) will be here Wednesday. Everything else I'm still waiting on.

A lot of things have happened in this build. Things really got out of hand

Edit: fixed the image size.



So I finished the lower for the rifle that has the Criterion barrel. Aero lower, Ergo grip, A2 stock, and Timney 660CE trigger. I'm still waiting for funds that I can redirect to buy a scope; I just had to buy a mattress, so it'll be a month or two.

The PSA lower that I was using before now sports a Del-Ton 20" upper that had a gas block transplant because the front sight post was interfering with the sight picture on the EOTech. Getting the FSP off was a fight; I couldn't get the taper pins off and ended up having to use a die grinder and a carbide burr to grind it down, then knock the pieces off with a cold chisel and a 3.5# sledge. I ended up biting the barrel just a little bit; nothing a little bit of cold blue and some oil couldn't fix. it's behind the gas block so it worked out anyway. The EOTech 512 is there to stay.

I built a third rifle with a locally-acquired tan Aero upper and lower, and used the Ballistic Advantage barrel that I previously modified. The gas block jig came in, and I dimpled that, as well. As you can see it's set up pretty close to the other 24" barrel, and I actually have another Criterion for when the BA barrel inevitably turns out to be garbage for precision shooting. The tan scope is only there until I can afford a nicer scope for it.

All 3 rifles work perfectly. Rocked them all with 69gr SMK handloads designed for my 16" Anderson AR. I wasn't focused on anything but function testing, so I didn't do much in the way of groups.

I've been getting set up to work up a load for the 69 and 75gr RMR bullets I'm switching to. Once I get the time to do some testing I'll start cranking those out. I've heard the 69gr RMRs are 5/6 of what SMKs are capable of; I'm curious to see what the 75gr are capable of.

That's cool the BA is a runner now.
Looks like a nice set.

I found that I like the A2 stock, I grabbed a new surplus OD green one and put it on my .308 instead of the Luth one I had.

Now I have a spare 5.56 A2 action and have been thinking of ditching the A5 for the A2 on my 18", I never collapse it anyway.

Mine seem to get rearranged every time I go shoot it a bit.
I think I'm almost there now, just trying to get the scope thing squared away myself.

Yeah, despite BA trying to deflect blame and say it was something else I knew it was the problem. They've been known to do this.

Pretty much the only reason I still have it in a rifle is because it has looser chamber tolerances than the Criterion barrels, and some 300-400 rounds loaded with the recipe from the 16" I don't own any more. The Criterion required me to drop the shoulder an extra 0.005" or so (I think; it's been a little bit) because I was having to mortar rounds out left and right. I can't wait to turn this to scrap and put the other Criterion on there.

Beautiful rifle. I like the A2 stock, but wish it were just a little bit longer. Like, if they made a back plate that were double thickness I'd have what I want. I rocked the B5 SOPMOD stock and always left it all the way out 24/7.