AR Troubleshooting (after swapping out uppers)

[golfish]

Ammunition used by me is:
American Eagle 55 grain FMJ.

Ammunition used by the team at Radical FireArms was
3 different ammo types .223 55gr wolf, .223 55 gr orr, and 5.56 62gr otm lead free Federal

Stated that it needed more gas, so the "port was opened"

How did it shoot when you got it back from Radical ?

Just wondering why you swapped out the buffer and spring, I guess it wasn't fixed when it was returned?

[G-forceJunkie]

Uppers and lowers have nothing to do with each other. Rifle length buffer tubes take rifle length springs and buffer. Doesnt matter what upper is on it.

Carbine length buffer tubes take carbine spring and buffer. Doesn't matter what upper is on it.

Gunsnrovers
The stock was a standard A2 buttstock, like this

https://www.aeroprecisionusa.com/a2-fixed-buttstock-black

but the upper was a 16" carbine length.

I had assumed, and later confirmed that the buffer and spring inside the A2 stock was for a carbine length upper.

Hope that helps clarify

[alpha_romeo_XV]

Probably safer to try this at the range with the muzzle pointed downrange, but have you tried just manually cycling 10 rounds through with the just the charging handle? That will test the extractor, ejector and magazine functioning. And from experience snap caps aren't that helpful in this kind of test.

I had a PC hard drive crash after moving stuff in a pod across the country so I've lost a lot of data on builds and reloading i did over several years - but i think i had trouble with a Radical upper. Good luck getting gas port diameter unless RF will tell you as most mfr don't list it in their specs. Or disassemble and measure it yourself, and that can also give a clue if gas block and port are fully aligned.

[jcruzin562]

You said it worked ok with the first magazine but not with the 2nd magazine. Did you try again with the first mag with no problems? And then again problems with the 2nd? If so is there a 3rd mag and how does it work?

[vf111]

I have a similar problem with a PSA 16" upper with mid-length gas. I'm pretty sure it's under gassed as it's not picking up the next round in the mag but is ejecting the spent casing. I eliminated the mags (tried three different mags with same issues). Ammo: Winchester WB, S&B, IVI surplus from the 1990's and Malaysian surplus from the 1990's. All had same problem. Lower has a standard carbine buffer and spring. I'll take the upper apart and check the gas block - I've read PSA uppers can have mis-aligned gas blocks.

[ar15barrels]

I have a similar problem with a PSA 16" upper with mid-length gas. I'm pretty sure it's under gassed as it's not picking up the next round in the mag but is ejecting the spent casing. I eliminated the mags (tried three different mags with same issues). Ammo: Winchester WB, S&B, IVI surplus from the 1990's and Malaysian surplus from the 1990's. All had same problem. Lower has a standard carbine buffer and spring. I'll take the upper apart and check the gas block - I've read PSA uppers can have mis-aligned gas blocks.

Make sure you do not have an O-ring on your extractor spring.
Many bolt carriers come with them but you should not use an O-ring on a midlength or rifle length barrel.
Also, new plastic mags will cause problems so use some metal mags or really well used plastic mags.
Lastly, new barrels and bolt carrier groups need a few hundred rounds of full power ammo to break-in before they will run reliably.
Make sure it?s well oiled.

[L4D]

Maybe it wasnt broken in yet and then they "fixed" it by openning up the gas port and now its cycling too fast?

[ar15barrels]

Maybe it wasnt broken in yet and then they "fixed" it by openning up the gas port and now its cycling too fast?

That's common.
The fix for that fix is an adjustable gas system or a selection of heavier buffers to experiement with.

[L4D]

That's common.
The fix for that fix is an adjustable gas system or a selection of heavier buffers to experiement with.

OP, I have two adjustable gas blocks for sale lol.