You see the Difference?

[Steve_evetS]

I bought a Satern 18" barrel and it came with a matching head-spaced bolt and after about 500 rounds I noticed the Lugs were wearing unusually. tell me if you see a difference in these two bolts.
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[montana]

I have seen this in an over gassed rifle and external piston..

It looks like it is unlocking prematurely from what I can tell from the pictures..Is there a gouge in the upper receiver cam lock pocket?

Look on the front of your barrel extension lugs and see if there are any marks or gouges too..The barrel extension could also be clocked..

[LRRPF52]

Does it have MLGS and .094” gas port? (Rhetorical question probably...)

MLGS with .094” barrel will cause very early unlocking and harsh treatment to the bolt, extractor, and brass.

You really have to choke the gas on an 18” if it has MLGS with a large port, which seemed to be the standard from Satern, not sure why.

That gas port should not be larger than .076”.

[Steve_evetS]

The gas port is .075 if you look i think the cam pin hole is misaligned in the satern bolt. Looks to be a degree or so off

[Steve_evetS]

Its a lil gassy but to be honest the bolt looks to be misaligned in the cam pin area a degree of or so

[Steve_evetS]

I have seen this in an over gassed rifle and external piston..

It looks like it is unlocking prematurely from what I can tell from the pictures..Is there a gouge in the upper receiver cam lock pocket?

Look on the front of your barrel extension lugs and see if there are any marks or gouges too..The barrel extension could also be clocked..

But do you see the difference?

[Steve_evetS]

Does it have MLGS and .094” gas port? (Rhetorical question probably...)

MLGS with .094” barrel will cause very early unlocking and harsh treatment to the bolt, extractor, and brass.

You really have to choke the gas on an 18” if it has MLGS with a large port, which seemed to be the standard from Satern, not sure why.

That gas port should not be larger than .076”.

But do you see the difference?

[LR1955]

Yo SES:

I don't see a bit of a difference.

You may be better served if you photograph the area of the bolt in question next to the bolt you believe is good.

BTW -- If I had to get an AR fixed or have one made for me, I would go to Montana or LRRP 52.

LR-55

[LRRPF52]

But do you see the difference?

I can’t see enough detail from the pictures of the bolts, even when I zoom, if that’s what you’re referring to.

[Steve_evetS]

I can’t see enough detail from the pictures of the bolts, even when I zoom, if that’s what you’re referring to.

I have confirmation that the bolt has a cam pin out of tolerance by 2 degrees I will keep you guys posted

[Klem]

I have confirmation that the bolt has a cam pin out of tolerance by 2 degrees I will keep you guys posted

Steve,

Maybe it's me but I'm still at a loss working out what exactly you're talking about.

[Darryle]

There is no difference in the orientation of the pin, you have the lugs facing each other, so the offset is just the opposite, place them side by side and you will see they are the same orientation.

What weight buffer? Standard H1 buffer? Go to a heavy buffer, I start at a H3 and go up, and slow down the cyclic rate, the extra weight keeps the bolt in battery longer.

FTR, I never use an adjustable gas block, I tune by buffer weight.

[montana]

Put a known good bolt into a carrier and push the bolt all the way in as if in lock up..

Mark the top lug to the carrier and then do the same with the bolt in question..

If it is clocked, you will see the difference..You can use the front of the carrier to mark the difference and use a protractor to find how many degrees it is off..

[Steve_evetS]

Are you guys telling me in the first pic you cannot see that the bolt in the back is clocked 2 degrees to the right? In the 2nd pic the one closest to you is clocked wrong?

[montana]

Do what I suggested to do and take a picture.. I'm sure we will be able to see how far it was clocked compared to the other bolt..

Or see if Chad will tell you how he got the (about) 2 degrees off diagnosis in his temporary fixture..

Later!

[Klem]

Steve,

I realize now what you're talking about. You think the hole for the cam pin in the bolt has been drilled offset to where it should be. It's not clear from looking at the bolt by itself in your photo.

I think you should heed Montana and marry the bolt under suspicion with a good carrier and see where the top lug is when pushed back 'into battery'. Like this photo - should be exactly 12 O'Clock, in line with the gas key.
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[Steve_evetS]

Steve,

I realize now what you're talking about. You think the hole for the cam pin in the bolt has been drilled offset to where it should be. It's not clear from looking at the bolt by itself in your photo.

I think you should heed Montana and marry the bolt under suspicion with a good carrier and see where the top lug is when pushed back 'into battery'. Like this photo - should be exactly 12 O'Clock, in line with the gas key.
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I will do what montana suggests. gotta wait for it to come back to me. I was hoping Chad would do a video of it

[Steve_evetS]

Steve,

I realize now what you're talking about. You think the hole for the cam pin in the bolt has been drilled offset to where it should be. It's not clear from looking at the bolt by itself in your photo.

I think you should heed Montana and marry the bolt under suspicion with a good carrier and see where the top lug is when pushed back 'into battery'. Like this photo - should be exactly 12 O'Clock, in line with the gas key.
[ATTACH=CONFIG]20117[/ATTACH]

the bolt in question is no longer available for it to be returned to me

[Steve_evetS]

I have seen this in an over gassed rifle and external piston..

It looks like it is unlocking prematurely from what I can tell from the pictures..Is there a gouge in the upper receiver cam lock pocket?

Look on the front of your barrel extension lugs and see if there are any marks or gouges too..The barrel extension could also be clocked..

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The Lug Wear in the first 2 pics the other three shows the URR going in and engaging the insert through the upper reciever. Which aligns perfectly. I am using the Midwest URR which has the sail.