AR pistol stove pipe problems!

[Nick_shoots_fast]

I got a cheapo pistol upper for Black Friday at a local shop and threw it on one of my pistol builds to function check. 
 

The gun keeps stove piping every 10-15 rounds and I can’t figure out why. I had a couple boxes of factory rounds that I used instead of hand loads just to see if it worked so the ammo isn’t the issue. These rounds also work in other pistol builds. I ripped everything apart when I got home today again to see if the gas tube along with gas block was properly aligned and that wasn’t the issue. I double checked to see if there was anything obstructing the gas hole in barrel and that was ok. Everything was oiled properly. Mag is brand new so it’s not the spring. Buffer system I believe is ok cause it works on other pistol builds. 
 

I can’t figure out what’s going on. This is the second trip to the range with this issue. The first time I thought the issue was the gas block cause it was a slightly out of alignment but it wasn’t. I can’t figure this out and was hoping someone can give me some guidance. 

[Yondering]

Stove piping is probably your ejector, or maybe the extractor. Pull the bolt and push the ejector in and out with a punch to make sure it moves freely and has plenty of spring pressure. Check for burrs and anything sticky or hanging up.

 

If that checks out, check the extractor too. If it seems ok, verify the extractor spring is adequate, and you may need the little O-ring around the spring to increase extractor tension if you don't already have one. 

 

The third possibility is that the gun may be severely overgassed. That can cause weird extraction & ejection problems that can look like undergassed symptoms. If your extracted cases have torn rims (or even partially torn) from the extractor, that may be an issue. A rough chamber can cause that too though and will be evident as small rings in the body of fired brass. 

Edited December 4, 2019 by Yondering

[Nick_shoots_fast]

6 hours ago, Yondering said:

Stove piping is probably your ejector, or maybe the extractor. Pull the bolt and push the ejector in and out with a punch to make sure it moves freely and has plenty of spring pressure. Check for burrs and anything sticky or hanging up.

 

If that checks out, check the extractor too. If it seems ok, verify the extractor spring is adequate, and you may need the little O-ring around the spring to increase extractor tension if you don't already have one. 

 

The third possibility is that the gun may be severely overgassed. That can cause weird extraction & ejection problems that can look like undergassed symptoms. If your extracted cases have torn rims (or even partially torn) from the extractor, that may be an issue. A rough chamber can cause that too though and will be evident as small rings in the body of fired brass. 

i didn’t know that about over gassing but I will check the bolt issues out when I get home. 
 

thank you so much for your advice! 

[CPD7119]

On 12/4/2019 at 7:29 PM, Atlasguy321 said:

i didn’t know that about over gassing but I will check the bolt issues out when I get home. 
 

thank you so much for your advice! 

What did you find out? What ended up being the issue?

[Nick_shoots_fast]

5 hours ago, CPD7119 said:

What did you find out? What ended up being the issue?

I just swapped out all the bolt parts but haven’t made it out to the range! Work has been crazy but hoping to go out Christmas Day. 

[CPD7119]

Keep us posted. I'm curious as to what the solution will be.

[assaulter]

 

The gas port size could be an issue, as well as the gas key on the carrier.