New thumper has an issue

[NightStalker]

Took the new 308 thumper out today and long story short it failed to lock back and cycle a new round. 
I figured gas issue on this adjustable gas block and figure maybe I messed up when I installed the gas block somehow. 
Got it home tear it down and believe the block to be fine. 
The gas tube extends about 1/2 way across the cam pin notch which should be right. 
Now I’m wondering if it was a mag issue, and didn’t think to try another mag. 
 I’m so confused lol. 

[308USK]

58 minutes ago, NightStalker said:

Took the new 308 thumper out today and long story short it failed to lock back and cycle a new round. 
I figured gas issue on this adjustable gas block and figure maybe I messed up when I installed the gas block somehow. 
Got it home tear it down and believe the block to be fine. 
The gas tube extends about 1/2 way across the cam pin notch which should be right. 
Now I’m wondering if it was a mag issue, and didn’t think to try another mag. 
 I’m so confused lol. 

@NightStalker, with the SAFETY ENGAGED and 2 rounds in a mag, can you manually cycle rounds with the charging handle?

[shooterrex]

If it is new you may just need to shoot a few more rounds till the gas block seals up.

What is your recoil system?

[NightStalker]

48 minutes ago, 308USK said:

@NightStalker, with the SAFETY ENGAGED and 2 rounds in a mag, can you manually cycle rounds with the charging handle?

I have not tried this but will when I can get into a safe area. 

[NightStalker]

20 minutes ago, shooterrex said:

If it is new you may just need to shoot a few more rounds till the gas block seals up.

What is your recoil system?

The recoil system is Aero Precision's M5 

[NightStalker]

32 minutes ago, shooterrex said:

If it is new you may just need to shoot a few more rounds till the gas block seals up

Is this common with the 308 AR’s? I have never had that issue with regular ARs but there is much more power in this platform. 

[shooterrex]

2 hours ago, NightStalker said:

The recoil system is Aero Precision's M5 

Aero uses 3.something oz  buffers. Not enough weight. What is the size of the gas port? Wide open adjustable won't do any good if the port is too small.

[98Z5V]

2 hours ago, NightStalker said:

The recoil system is Aero Precision's M5 

Rifle Recoil System?  Carbine Recoil System?  "Aero M5" has both.

Yes, carbon fouling in order to form a gas seal is normal.  How many rounds out of this gun so far?  Total...

These aren't AR15s... 

Edited July 17, 2022 by 98Z5V

[NightStalker]

3 hours ago, 98Z5V said:

Rifle Recoil System?  Carbine Recoil System?  "Aero M5" has both.

Yes, carbon fouling in order to form a gas seal is normal.  How many rounds out of this gun so far?  Total...

These aren't AR15s... 

Recoil system- Aero M5 carbine

Round count- 42 

Not sure about the gas port size and that’s a great point I didn’t think about. I can tell you I checked to see if it was blocked with a 1/16 punch slips in it.

What size port should it be?

 

I took it back out this afternoon and it was loosening up and cycling like it should. It still failed to hold open on the last round.

I know it’s not broken in yet

 

[98Z5V]

28 minutes ago, NightStalker said:

Recoil system- Aero M5 carbine

Round count- 42 

Not sure about the gas port size and that’s a great point I didn’t think about. I can tell you I checked to see if it was blocked with a 1/16 punch slips in it.

What size port should it be?

 

I took it back out this afternoon and it was loosening up and cycling like it should. It still failed to hold open on the last round.

I know it’s not broken in yet

 

Gonna need details on the whole gun, just like we tell everyone else that states operational issues.  Start by reading this - and comply with the details needed...

YOU have to tell US what you have - so we know what we must work with.  That, right there, is the very "step 1" in the whole process.  Otherwise, it's just guess-work.

Read this:

 

[NightStalker]

Ok here’s the complete run down on this rifle:

Upper- Aero Precision standard upper 

Barrel- Ballistic Adv. 16 in 1/10 mid length gov cut

BCG- Ballistic Adv.

Charging handle: Aero Precision 

Gas Block- Seekins Adjustable 

Gas Tube- 113/4 in mid length

HG- Midwest industry 12 free float

Lower- Aero Precision

 Buffer- Aero Precision mil spec 308 carbine buffer tube with carbine spring and weight   

parts kit- Aero Precision with Mag Pull grip

Butt Stock- MagPul ACS Adaptable Carbine 

I tried to keep everything Aero or Ballistic Advantage with the major parts since the two companies are related

the Seekins gas block was used because I was familiar with them since they work great on my other builds

Also not trying to be a smart a** thought this would be a good place fo a complete list all the parts in it just for my records. 
I think that’s everything 

[shooterrex]

That recoil system is not good.

You need a heavier buffer and a proper spring.

Still need to know what diameter you gas port is?

[NightStalker]

39 minutes ago, shooterrex said:

That recoil system is not good.

You need a heavier buffer and a proper spring.

Still need to know what diameter you gas port is?

What recoil would you recommend?

I’ll have to call BA tomorrow, no time today to tear the GB off to measure the gas port.  

[shooterrex]

https://www.armalite.com/SACItem.aspx?Item=AR10REKIT01&ReturnURL=/Armalite/Product-Category/AR10-Parts-Accessories/Lower-Receiver-Parts&Category=ac614400-ff09-4cdf-9d35-419a654e7201

[shooterrex]

Aero can tell you what they think the gas port diameter is but the only way to know for sure is to measure it yourself.

[NightStalker]

1 hour ago, shooterrex said:

https://www.armalite.com/SACItem.aspx?Item=AR10REKIT01&ReturnURL=/Armalite/Product-Category/AR10-Parts-Accessories/Lower-Receiver-Parts&Category=ac614400-ff09-4cdf-9d35-419a654e7201

So if there’s not enough gas and I put a heavier buffer and spring in it, won’t it short stroke?

[shooterrex]

Yep they need to be balanced.

The Armalite parts just work if your gas system is correct.

The bolt not locking back w/a light buffer tells us your gas port is too small.

When you open that up it will overpower the light recoil system causing other function problems.

Both ends of the gun have to work together.

[98Z5V]

3 hours ago, NightStalker said:

So if there’s not enough gas and I put a heavier buffer and spring in it, won’t it short stroke?

Read this, man...
 

 

[NightStalker]

Ballistic Advantage said the gas port should be .0730, and if I figured it right isn’t that between 1/16 and 5/64?

Ya I’m not good with math anymore lol. 

[shooterrex]

https://www.google.com/imgres?imgurl=https%3A%2F%2Fi.pinimg.com%2Foriginals%2F86%2Fcc%2F77%2F86cc774c07605d94f459484dbc8487fa.png&imgrefurl=https%3A%2F%2Fwww.pinterest.com%2Fpin%2F452119250066062019%2F&docid=bEJSWzIIARIMAM&tbnid=-gmUVjD3dp8pNM&vet=1&w=340&h=767&itg=1&hl=en-US&source=sh%2Fx%2Fim

[NightStalker]

That helps, I’ll check the hole size tonight and post what I find. 

[Armed Eye Doc]

6 hours ago, NightStalker said:

That helps, I’ll check the hole size tonight and post what I find. 

Things you can say about your gun but not your wife/girlfriend.  

[NightStalker]

1 hour ago, Armed Eye Doc said:

Things you can say about your gun but not your wife/girlfriend.  

Bahahaha ya that could be an issue lmao 🤣 

[NightStalker]

Looking at the gas port 1/16 to small 5/64 is to large so I’d say it’s .0730. 

What size should it be for proper operation?

[NightStalker]

                    Update

did some gas chamber work on it this last week and took it out yesterday. It did great after a couple turns on the gas block, including locking back. 
I want to thank all who gave input And guidance. It is  greatly appreciated