Gunsmithing Early abnormal Bolt Wear.

[Fishcreeker66]

What causes this type of wear on the bolt. Gun is a PSA 10. Had this same kind of wear after around 150 rounds. only quite a bit worse. Sent it back. They put a new barrel on and complete new bo
lt carrier group. Possibly heavier spring and buffer but not for certain. They didnt send a list of what they did or the cause of the issue. I have fired about 80 rounds threw it this weekend and its starting to eat the bolt again. Im guessing over gassed and opening to soon after the round is fired but im not a gunsmith. Any help is appreciated.

 

[Lawless]

Does it have an adjustable gas block?

What buffer?

@bfoosh006

 

[KZP]

How does the cam pin slot area look in your upper? Is the metal galling?

 

[Fishcreeker66]

How does the cam pin slot area look in your upper? Is the metal galling?

Here's a picture of the buffer and spring. No markings on the buffer.

 

[Fishcreeker66]

Cam pin and cam area look fine. Little wear on the finish of the cam pin but looks normal. I've got 2 RRA ar15's with about 1500 rounds each on them and they show none of this.

 

[Lawless]

I am no expert on big ARs, just have owned a few DPMS 308s in the past.

Almost all big ARs are over gassed badly. An adjustable gas block along with a Tubbs Flatwire SR25 spring and at least H3 5.4oz buffer will help mitigate the early bolt unlocking.

Where is your brass landing? Around 4 o’clock is optimal, if forward of 3 o’clock it is most definitely overgassed.

Now I cannot say this is causing your bolt wear, but it stands to reason it could contribute.

http://www.davidtubb.com/bufferspring-sr-ar10?search=Spring

 

[Fishcreeker66]

Brass is landing at about 2 o'clock. It has a heavier spring as well as a longer buffer than my Bush Master ORC .308. No markings on the buffer. Im going to call them today and send it back again. Then when i receive it back put an adjustable gas block on it.

 

[Fishcreeker66]

 

[GH41]

Try to get them to give your money back then buy a better rifle.

 

[bfoosh006]

Interesting... are the other lugs banged up as well ?

 

[bfoosh006]

Photos of all the lugs please.

And does it feel overgassed ? ... or how is the recoil impulse ?

 

[Fishcreeker66]

Photos of all the lugs please.

And does it feel overgassed ? ... or how is the recoil impulse ?

Pic of bolt kn first post. Recoil feels eccessive. Waiting on a call from them.

 

[Fishcreeker66]

Interesting... are the other lugs banged up as well ?

Not as bad but another 100 rounds and i think they would be.

 

[KZP]

Brass is landing at about 2 o'clock. It has a heavier spring as well as a longer buffer than my Bush Master ORC .308. No markings on the buffer. Im going to call them today and send it back again. Then when i receive it back put an adjustable gas block on it.

2 o'clock seems pretty rough. I have tuned my AR10 glas block to just barely lock my BCG open on the last round and it ejects about 4 o'clock.

 

[Fishcreeker66]

Try to get them to give your money back then buy a better rifle.

2 o'clock seems pretty rough. I have tuned my AR10 glas block to just barely lock my BCG open on the last round and it ejects about 4 o'clock.

I plan to put an adjustable gas block on it after it gets sorted out. I would take a refund if they would give me one. We'll see how it goes.

 

[Sam Dunham]

I do not know PSA well but have been reading reviews and I wonder if they shoot their products in test and eval in all conditions with thousands of rounds before they let a design go to production and quality control checks during production? I almost bought a Gen 2 AK from them but if they cannot even get the barrel pressed in straight enough to have the front sight in the correct vertical plane it makes me wonder if they pay any attention to detail at all? They should have known the Trunion needs to be forged in the beginning when the Rob Ski gen 1 Gun was peening? They are not shooting their stuff enough to know.

 

[bfoosh006]

Not as bad but another 100 rounds and i think they would be.

@Fishcreeker66

I just checked all of my BCG's in 7 firearms, and every other brand BCG I have used / tested... AIM, Brownells, Toolcraft.. nitrated , NiB, phosphated.( All fired with PSA builds, variety of barrels Criterion, BA, FN, and lengths, gas length systems.

Zero of them had any form of battering yours shows.

Nothing even close.

 

[bfoosh006]

At this point, if all the bolt lugs are showing battering... I wonder if the cam channel is cut correctly.

Can the OP check inside the upper receiver for any odd marks , at all , at the cam channel areas.... or anything that might be restricting free movement of the cam pin through the upper... maybe the bolt is not freely, fully locking in place.

Also please weigh your buffer.