Are you sure the correct buffer spring is installed?

Do you have a recommendation? I welcome any ideas you have.

Looking at Aero Precision’s web site, they have a chat function. They also have a customer service phone number. You might want to contact them and see if they will repair it under warranty.

I haven’t had the need to use their customer service much, but when I did, it was top notch.

On AR15's an extra "something" with the extractor spring is often the fix for carbines with dwell/extraction issues. I wonder if they don't know this from the get go and add the second ring proactively.


Your "hard to work the bolt" comment reminded me years ago of a used upper I bought that the gas tube was completely in front of the pin. So it was jammed in the carrier and when you pulled it back with considerable difficulty, the gas tube went with it. I doubt that's your problem though, since you've had more than one.
Wondering if you got something in your gas key and that's what gacked the first tube. Stranger things have happened.

I used the chat function to contact their customer service. They gave me an address to send the upper and said they would look it over and repair whatever needed to be fixed. I provided an invoice number, which they said they couldn't find in their records. I'll send a copy of the invoice. It would be great if this was a warranty repair but I'm far more interested in getting the darn thing to work reliably.

As to the possibility the gas tube is jamming on the bolt. There is no sign of deformation at the tube.

I'll let you guys know when the upper comes back from Seattle.

Who built the lower?

Sorry to hear it was still not working right. Yes, please give us an update once you hear back from them, or get it back with what they had to fix.

quote:

Are you sure the correct buffer spring is installed?

Walker77 asked a great question. I assumed it was correct It fit and came from a nationally recognized supplier of AR platform parts. Still, I couldn't say it was correct.

I went to the web and I started researching AR 308 issues and found myself at https://heavybuffers.com . I called them and left a message. About 30 minutes latter, Clint called me back. We spoke for a while, it was obvious he felt his buffer and spring would help me with this problem. I ordered a heavy buffer and a new recoil spring. I had to wait til this morning to have the time to go down to the range.

I just put 20 rounds through it without a malfunction! Felt recoil is much the same as before.

I had purchased a different brand of magazine to try as well and the change in magazines did not cause a malfunction.

This message has been edited. Last edited by: Wasabibill,

Glad you got it working!

This is an update.

Getting this rifle to function properly has been hard/disappointing. I thought my problems were resolved with the heavy buffer which I installed in September of 2024. The type two and type three malfunctions continued... I replaced the gas tube, replaced the buffer and spring, bore scoped the barrel and chamber, and replaced the springs and ejector on the BCG. All this time I was finding it very difficult to operate the charging handle because of pain in my fingers and hands. I was diagnosed with rheumatoid arthritis in early December.

I fussed with this for all of October and November and ultimately concluded the next logical place to go to for help was the manufacturer of the Upper, AeroPrecision. Their customer service is awful in every sense of the word. They have a phone number for customer service, but if you call the number they refer you to their website. The website has a chat function which was probably attended by a chimpanzee. I wrote multiple emails to them and one day got a message back saying I could send the upper to their address in Washington. No RMA, just send it. I did. (By the way their website no longer has a chat function).

I got a confirmation the upper had been received on 12-4-2024. No acknowledgement from AeroPrecision at any time. I wrote them a number of emails trying to get some sense of the progress, if any, on the diagnosis and repair, with no response. I was, to put it mildly, bent.

On Wednesday, I called AeroPrecision and was put on hold. While on hold I went to my email to get the email string in front of me so I could complain. In the email I found a message from AeroPrecision which said,

"Feb 5, 2025, 1:15 PM PST

Hi Bill,

Apologies for the delay. Our gunsmiths have reworked your upper receiver and found that the through bore of your BCG was oversized, resulting in your cycling issues.

We have installed a new BCG and your upper was test fired and function tested without issue."

All of this is covered by their warranty. FedEx says I will get the upper back on Monday. I'm going to the range on Tuesday!

If I can run two, 10-round mags, through this without a malfunction I will be on the road to joy. The accuracy of the rifle is excellent. I'll let you know.

I hope your issues are resolved and you end up with a reliable AR10.

To anyone else wanting to embark on such an endeavor I would refer them to just buying a complete PSA upper/lower combo. Mate it together, clean and lube it and take it to the range.
They are good to go and the pricing is unparalleled for such a rig.

https://sigforum.com/eve/forum...0601935/m/8600063315

“the through bore of your BCG was oversized”

Huh? How would that cause the issue you described? Was the bolt wobbly when sliding in the carrier group?

No, the bolt didn't wobble in the bolt carrier.

I don't think I've put 50 rounds through the rifle since I put it together and there was no sign of wear.

The repaired upper was delivered last night. I hope to have the time today to take it to the range and see if it functions reliably.

As to the suggestion that someone purchase one of these AR platform rifles pre-built and ready to go. I put together an AR-15 and was pleased with the experience and expected a similar result. There is a huge difference between an AR-15 and an AR-10. After all of this misery I would recommend you buy one assembled. It will be easier, more reliable and probably less expensive than what I've experienced. Also, I wouldn't recommend Aero Precision.

I just got back from the range.

The rifle functioned without a hitch and the bolt locked open at the end of each magazine.

That is great, continue to get it broke in. You should be good.

Sounds like the barrel was overtightened and it twisted the pin until the barrel was out of time with the bolt.

Gents,

The problem would be solved if he were shooting an M-14/M1A...

Wes

Believe me, in the deep winter of my discontent, I spent a lot of time looking at at those platforms. Ultimately, I concluded if I couldn't get the darn gun to work reliably I would leave it to my least favorite child with a note that said, "Here's this gun, I love you, I'm still mad you totaled my truck".

quote:

Originally posted by flesheatingvirus:
“the through bore of your BCG was oversized”

Huh? How would that cause the issue you described? Was the bolt wobbly when sliding in the carrier group?

The throughbore they're referencing is likely the smallest diameter section of the carrier, where the bolt's tail interfaces. Having the bore too large would decrease the available gas to drive open the bolt/carrier. Essentially undergassing the gun.

Hopefully this image works, but here's a cutaway of a standard AR15 BCG, with the pointer on the bolt tail as it sits in the throughbore. You can see the gas chamber in the carrier, fed by the gas key.
https://i.ytimg.com/vi/Uv6a1hs9U5o/maxresdefault.jpg

quote:

Originally posted by Weshowe:
The problem would be solved if he were shooting an M-14/M1A...

Yeah, but now that this issue is behind him, he has the following advantages of the AR10 platform over the M14:
- Greater accuracy potential
- Easier to maintain accuracy over the rifle's effective life
- More modular
- More talented gunsmiths who can work on the rifle
- Easier to mount a scope
- Cycling is less affected by suppressors
- Less picky with ammo
- More options with barrel lengths and profiles
- The ability to change uppers
- Greater number of parts suppliers
- Many caliber options, requiring only relatively simple barrel changes