AR-15 Gas Issues! Attention AR Docs!

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My suggestion would be the following, however you have bought a Noveske barrel with an at factory staked gas block correct?

If I were you I would disassemble the upper and start again from scratch on assembly. I would pay extra attention to measuring the gas port and location in relation to gas journal shoulder and verify the port on your gas block that it is exactly 180* from the gas tube alignment and with the proper location from edge of gas block to ensure it will align with the barrel's port. I would check for any manufacturing burrs in the gas port and gas tube. It sounds like this is not your first AR so you should have some known good running AR's to check measurements with.

Given that you've tried a known lower that is properly functioning with this upper and still have the same issues that would satisfy me on there not being an out of spec situation on the lower that is allowing the magazine to either sit too high or too low causing friction on a cycling BCG or not allowing the follower to activate the bolt catch.

To me it sounds like a barrel gas port, gas block, or blockage type of problem based on what you've already attempted on troubleshooting.

You said you've changed carriers have you tried a different bolt? Just for S&G's.
 
The carbon tattoo on the gas port is perfectly centered and uniform. No burrs on port (inside and out), gas block and tube are clean.

But I did notice something. Firing pin protrusion was on the low side of acceptable. I pulled out the bolt and checked OAL against another one, it was identical. But the firing pin had more of a radius where it contacts the tail of the bolt. I chucked the firing pin up in the drill and removed part of the radius with a jeweler's file being careful not to change any other dimensions.

Just got through first mag with no light primer strikes. Primers look normal, no puncture or over penetration. Time will tell if this was a fix, or a bandaid.

We will see what a h3 buffer does for my gas issues. If it remedies the symptom, then I will try one of the gas block inserts to remedy the problem.
 
Sorry...been on vacation.

So got home and my H3 buffer weight was waiting on me. After a 30 round test, this has tamed recoil slightly, reduced gas in face, and moved ejection to 2:30 with a 4 foot distance while standing unsuppressed. No malfunctions. Recoil is still more than any other AR in my experience. Ammo was lake city xm855.

As this was only a quick 30 round test, and did not try suppressed, as of now I only consider this an improvement and am hesitant to consider the issue resolved. I need to get a few more hundred rounds. If not satisfied by then, my next step will be the BRT reduced gas port. But I will only do this once I am able to perform an accuracy test to see if this is worth my time. I am close to just selling the barrel at a loss (with full disclosure) and going with another manufacturer.

Due to the initial issues, lack of customer support, blaming a competitors part, lying to me saying it's fine, and returning a still defective product I am done with Noveske. Just too many (expensive) headaches. This was a $430 barrel, + paying to ship it back to Noveske puts me in the $450 range. I know there are many out there that are flawless, I don't dispute that, but a quick search shows there are also quite a few overgas issues as well as QC issues since John passed (R.I.P.)

The only other problem I have ever had building ARs was many years ago with a DPMS chrome BCG, that the THR community help me solve.
 
Noting this thread for the next time someone asks about building an AR for their first AR.

Don’t build one, buy one.
I agree...I didnt build my first until I bought one as a reference to see where everything was supposed to go. An oly ban era plinkster if I recall correctly.
 
Sorry you’re having issues with it.

Try a Sprinco red spring in it and the H3 buffer.

As for your BCG, I wonder if they used Permatex sealant where the gas key mates to the carrier? TDP calls for this, and it helps. Between properly torqued and staked gas key screws, and Permatex you should get no leaks there.
 
I don't see anywhere in this thread where the gas port has been measured. Maybe I missed it. The only way to determine if it's over gassed is to measure the port. Assuming the gas port is too large the correct way to fix that is to make it smaller by using an adjustable gas port. H3 buffers are seldom used and usually not needed.
Have you tried some old fashion GI spec mags? The only mags that fail me or cause any problems are the after market ones.
FTF from a light strike is either the hammer spring, firing pin or the bolt is just slightly out of battery. One thing that is often over looked is the alignment of the gas tube. If the barrel nut is slightly misaligned it can cause the tube to be misaligned.
 
.088" gas port.
Barrel nut does not require indexing, and does not contact gas tube. Gas tube is center, no uneven wear.
Mags tried: known good pmags, center,okay, D&H
 
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0.088" gas port is higher than what reputable companies drill for a 16" mid length. Most companies seem to fall between 0.072" - 0.082", your Noveske barrel IMHO has a port that is too large for the length of gas system and barrel. Also, with gas port erosion over time, this is only going to get worse. These are just my observations from my own research and looking at manufacturers recommendations. Even on the high end of the recommendation above (the 0.082" port) most are seemingly having to run at least H or H2 buffers, so an additional 0.006" that you have would put you into a harsher recoil and thus showing why you saw a perceived improvement going to the H3.

On a "battle rifle" or in other words a rifle that you may have to stake your life on I always err on the side of making sure it will reliably lock back on weak ammo, such as Tula 55 gr. .223, and call it a day.

I would demand my money back, and if Noveske's reputation is worth anything (and it better be for the price one pays) their customer service will step up and take care of you, as you have shown you've done quite a bit of work to get this working properly. If they won't take it back, I think your options are an adjustable gas block or threaded port like was suggested.

Personally, if Noveske refuses to stand behind their product they would hear from me that we are in a mature market with the AR15 and there are many great barrel manufacturers that are just as good or better than Noveske without having to pay for their name (these are my opinions). This is not to say that Noveske doesn't build good barrels, but a portion of your money is going to prestige in my opinion. And with John Noveske no longer at the helm maybe they are slipping a bit, who knows.
 
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Is this a mid length or carbine length?
Mid = .08
Carbine = .075
I have a mid length that is around .071. It shoots like a BB gun reliably with a H buffer.
 
Wondering if a good test would be to get some Wolf or other low power ammo and see how it runs. If it runs better with low power ammo, then we know it's over gassed.

Also is .076 too big? Should I go for one a little smaller?
 
It’s quite disappointing to read this thread. My experience has always been that when companies get to that “cream of the crop” status the mentality follows suit. Sounds like that may be the case here, reputation was earned but now it is slipping. I know of a Noveske barrel that had issues which were handled by drilling a new port and turning the barrel to create a custom length gas system. Old port was tapped and sealed. Gun is immaculate now, and shoots better than it looks, but one has to ask if it’s really worth the headaches.
 
Hmm, I'm surprised no one suggested to check the bolt catch spring. I had one that was too stiff, and the bolt wouldn't lock back reliably. I just took a turn or so off the spring, and she's run like a champ.
 
Didnt think of that, just checked. Bolt catch tension and movement is on par with others.

Also to add, the lower pictured I just built today so I could try a completely different lower. Built with BCM lpk. Runs the same on RRA, Noveske, and Aero lower receivers.

As of now I am running a Geissele Super 42 with H3 buffer. Geissele states their spring is 15% stronger than standard spring. I am getting 2:30 ejection and 1:00 while suppressed. But I am up to 120 trouble free rounds. I plan on wringing it out tomorrow and re-sighting irons and acog.
 
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