Ar-15 barrel damage

[supercorndogs]

Has anyone ever had barrel extention damage on their ar15? Here is your chance to tell your story. I have never seen it before, but now I have had two barrels in row show the same damage. What damage have you seen and what caused the damage?

My second barrel is showing damage after 20 rounds of 6 arc shooting 25.5g of varget with a 90tgk at 2550. I have seen 223 wilde barrels that have shot several rounds that blew primers and they don't show any deformation on the feed ramps.

My last email i was told.

"What buffer and buffer spring are you using? If that's 20 rounds that's a good amount of carbon which combined with the feed ramp is indicative of very fast/high pressure extraction. Are you running this suppressed?"

My ejection is about 4 0clock 5 or 6 ft away just like my other tuned rifles.

I have seen carbine gas systems running way too fast ejecting almost straight forward for hundreds of rounds show no damage to the barrel extention.

The first two are the new barrel and compares the deformed side to the good sid. The second are the old barrel with about 400 rounds.

 

[Ernest 5.56]

Sir just for the record

Are you using the same bolt with both barrels?

 

[supercorndogs]

Yes. Rainer asked for all the parts i used. I sent all the parts to Rainer. They replaced the barrel, test fired it, and sent it back.

The bolt looks fine. I am not sure how the bolt would cause the damage. I am pretty sure the extention should be the stronger of the two parts correct?

 

[supercorndogs]

Could it be the carrier and an extraction timing issue? I am digging looking for something other than the barrel extention. It seems quite unlikely two are bad, but if two are bad the implacations are pretty bad.

I was thinking about replacing the bolt and carrier for the next one, but comparing the carrier to the one in my Grendel there is no obvious diffrence in the area the cam pin runs. I assumed inspecting these part was why Rainer wanted them.

Brass is at 3x and primer pockets are still tight.

Could the coating or treatment on the barrel extention soften the surface and let the lugs sink in.

I don't see what I could have done to it in 20 rounds or how a part that could damage it that much in 20 rounds wouldn't be obviously damaged as well. I mean would 20 proof loads even do that? Would it set back or break some lugs first?

Does anyone else have a Rainer ultra match 6 arc they can check?

 

[Rocketvapor]

I don't remember which gun forum, or thread, but I read a few days ago about one Vendor (?) with suspect SOFT extensions doing the same thing.
Was that you?

 

[bigjake83]

My guess, it's a batch of Barrel Exstenions that didn't heat treat properly and are super soft.

I've never seen that shit before, since it's a Rainier Arms Ultra Match send it back to get a refund. Craddock Precision is making those barrels now maybe it's something on his end.

 

[bigjake83]

Does the bolt have any damage?

 

[supercorndogs]

My guess, it's a batch of Barrel Exstenions that didn't heat treat properly and are super soft.

I've never seen that shit before, since it's a Rainier Arms Ultra Match send it back to get a refund. Craddock Precision is making those barrels now maybe it's something on his end.

The bolt doesn't look damaged. The thing is I bought the first barrel a year ago. And this new barrel I assume was just made.

I may send it back. I have already been shopping for a replacement.

 

[supercorndogs]

I don't remember which gun forum, or thread, but I read a few days ago about one Vendor (?) with suspect SOFT extensions doing the same thing.
Was that you?

I had another thread where I was asking about the upper receiver then when I took it apart I found the barrel extention damage. 357max said he had the same problem with a Rainer UM. It wouldn't be very noticeable if one were shooting factory ammo or not watching shoulder bump and growth batch to batch.

 

[Bluedog82]

I’ve been having trouble with a Ranier match barrel in 6ARC also. It does not want to go fully into battery, I’ll get a click (no FP strike on the primer), and then I’ll have to mortar the damn thing open with a mallet. Does this with multiple magazine, two different bolts and BCGs, and two different buffer setups. Very frustrating.

 

[Bantam1]

That TiN coating is applied at around 800F. Maybe that is creating an issue with the hardness?

 

[Rocketvapor]

A couple years back I read about extension treatments that required high temperatures that made them softer.
Same thing with AR bolts. Some coatings sound cool but may be hot.

 

[supercorndogs]

I’ve been having trouble with a Ranier match barrel in 6ARC also. It does not want to go fully into battery, I’ll get a click (no FP strike on the primer), and then I’ll have to mortar the damn thing open with a mallet. Does this with multiple magazine, two different bolts and BCGs, and two different buffer setups. Very frustrating.

Sounds like the ammo is too big for the chamber. I.E headspace or body diameter is too small in the barrel or too big on the ammo.

 

[Bantam1]

The same friend that worked at Surefire said they sent some parts out to be S-Line? coated because it's supposed to be excellent and applied at lower temps. The parts came back soft and had issues. The applicator place wasn't sure what temp they applied it at...so could have been just that place. Either way it wrecked some parts that were hardened to whatever spec they had. The alloy should have been fine at the temps they advertised. Somehow it didn't happen the was it was supposed to. I suspect that can happen anywhere.

 

[supercorndogs]

A couple years back I read about extension treatments that required high temperatures that made them softer.
Same thing with AR bolts. Some coatings sound cool but may be hot.

I was thinking I read something constructor posted about it one time. Where he was talking about getting some barrels nitirded with the extentions on them and the barrel extentions unscrewed by hand aftwards.

 

[supercorndogs]

Rainer is telling me they normally only see this in guns running way too fast. I don't know if @Constructor would be kind enough or have the time to comment.

I don't think my gun is running way to fast tuned with an adjustable gas block to just lock back on an empty mag. Same lower buffer and spring I use on my grendel. H3 with a carbine spring. Second barrel was h2 with a strike industries flatwire spring.

 

[Ernest 5.56]

Rainer is telling me they normally only see this in guns running way too fast. I don't know if @Constructor would be kind enough or have the time to comment.

I don't think my gun is running way to fast tuned with an adjustable gas block to just lock back on an empty mag. Same lower buffer and spring I use on my grendel. H3 with a carbine spring. Second barrel was h2 with a strike industries flatwire spring.

How far does your gun throw the brass?

 

[supercorndogs]

Probably 5-6 feet. Just like all my others. I could draw about a 12" circle on the ground a little behind my bench and I think all my rifles would hit the same circle. 223s, 224 Valkyrie, 6.5 Grendel, 20 practical.

 

[Cascade Hemi]

Rainer is telling me they normally only see this in guns running way too fast. I don't know if @Constructor would be kind enough or have the time to comment.

I don't think my gun is running way to fast tuned with an adjustable gas block to just lock back on an empty mag. Same lower buffer and spring I use on my grendel. H3 with a carbine spring. Second barrel was h2 with a strike industries flatwire spring.

If they're trying to say the gun is unlocking early, you'd have heavy extraction marks on brass and feeding issues. Lugs don't even deform like that from proof loads.

 

[supercorndogs]

This is the last email they sent me.

"Are you tuning the gas block for ejection direction/pattern or to just lock open on empty? Generally what you're seeing is something that we only see on guns that are running significantly faster than they need to be, and if that's not what is going on with your rifle then I'm honestly baffled as to what is going on."

 

[bigjake83]

Rainer is telling me they normally only see this in guns running way too fast. I don't know if @Constructor would be kind enough or have the time to comment.

I don't think my gun is running way to fast tuned with an adjustable gas block to just lock back on an empty mag. Same lower buffer and spring I use on my grendel. H3 with a carbine spring. Second barrel was h2 with a strike industries flatwire spring.

With everything you've listed I'd say that's not the case. Can't remember are you running suppressed?

Regardless that's unacceptable, get your money back and switch to Proof SS or V Seven if you're wanting a lighter barrel.

I really hate these threads, I know a custom barrel is $200 more but you sure don't see these issues.

 

[supercorndogs]

New chamber as received 1.185
Old ammo from die set up after firforming 100 peices of 6.5 grendel brass. 1.190. Last brass fired in the first barrel 1.202.

 

[supercorndogs]

With everything you've listed I'd say that's not the case. Can't remember are you running suppressed?

Regardless that's unacceptable, get your money back and switch to Proof SS or V Seven if you're wanting a lighter barrel.

I really hate these threads, I know a custom barrel is $200 more but you sure don't see these issues.

Thank you. I will check out v7. I have sent a few emails back and forth with x-caliber also.

I do shoot with a suppressor.

 

[Jsp556]

I remember @Constructor saying he was worried about the possibility of melonited extensions being soft and lugs compressing so he stopped using them and started using raw extensions. I “assume” this is what he was worried about.

The first couple barrels I bought from him, 2015-16 timeframe, had melonited extensions. I gave one away that I tried to kill that showed no signs of lug compression and still have one with a melonited extension that has a few thousand rounds through it and it seems fine as well. Every one since have had raw extensions.

 

[supercorndogs]

@357Max have you checked your replacement 6 arc barrel? You wouldn't happen to know who you talked to at Rainer would you? The guy I am talking to says he is not aware of them ever having a material problem with a barrel extention. And if there were problems with them they would see a lot of them because they come from limited batches. The implacation being that this is being caused by something I am doing. And advising me to use a heavier recoil spring. And wanting to ask their gunsmiths about what ever ammo I am using.

 

[357Max]

@357Max have you checked your replacement 6 arc barrel? You wouldn't happen to know who you talked to at Rainer would you? The guy I am talking to says he is not aware of them ever having a material problem with a barrel extention. And if there were problems with them they would see a lot of them because they come from limited batches. The implacation being that this is being caused by something I am doing. And advising me to use a heavier recoil spring. And wanting to ask their gunsmiths about what ever ammo I am using.

Mike S is who I dealt with.

Below are excerpts from my correspondence with them in reverse order.

As you can see I stressed they had a heat treat problem with the Tin coated extensions.

I did receive the replacement, but only have 40 rounds on it.

Mike,

Following up on this. Called last week on the 13th & spoke to someone. He said he’d been trying to head space a new barrel to the old bolt. Told him to give up as that bolt was just sent so you would have the full picture. He said A new barrel would ship Tuesday the 14th? Haven’t received any email or tracking. Has this shipped?

Thanks

Mike,

Thank you for the reply.
I would prefer you just replace the barrel. If the replacement barrel extension can easily be verified for heat treat by your shop that would be fantastic.
The barrel was shipped today using your label. You should receive it Tuesday 3/7. Tracking #

I did include the Maxim bolt that was run with the barrel. If possible I'd like the bolt returned with the new barrel. Ejector + spring & extractor were tuned and I'd like to recycle them for spares.

Not sure if your shop has the ability to perform a Rockwell test on the extension, but I would suggest doing so. It's a very high probability this was the result of improper heat treat by your extension or heat treat vendor.

Build specs below for ref.
VLTOR Fusion F-15 monolithic upper, receiver face trued, extension thermal fitted with 1 full wrap of SS .001 shim stock
Odin works adj gas block & + 2" gas tube.
Rubber City light weight bolt carrier, FP, Cam pin
Maxim type 2 6.5 Grendel bolt
JP silent capture buffer system std weight + standard spring
Magpul PRS gen 3 stock + spacer for silent capture.
JL billet ambi lower
Trigger Tech single stage & ambi selector

Gas block was running pretty close to the center of adjustment range.
The ejection pattern was 4:00
BCG over travel was checked and good.


Attn: Mike
Total round count on barrel is 446. FWIW the receiver face was trued and the barrel was installed with 1 full wrap of .001 shim stock. Lug contact was even & I always run lube on carrier and lugs. When new head space with new Maxim bolt was Go plus at most .001. Now it's go plus .0013

Per our conversation please see attached pictures of the barrel extension. The pictures are in the following counter clockwise order looking from the back.
3, 1:30 (extractor lug), 12, 10:30, 9, 7:30 (might have to stare at this one for a minute), 6, 4:30.

1 picture of 12 oclock lug on Bartlein with 100 rounds on it for reference.

Pictures of the bolt lugs & top.
Back of extension showing metal displaced back on bottom 3 lugs

I think the extension was either improperly heat treated or Tin coated without heat treat. Hopefully you didn't get a big batch of the same. I have a lot of AR's and have never seen this happen before.It was gaining almost .003 HS per 100 rounds. I do not trust this to continue running it. I spoke with one gentleman who's broken 3 bolts each @ about 1000 rounds. Each time a new bolt head spaced to the barrel i.e. no extension wear. He was also running Varget which IMO is too fast a powder for ARC so I'm not that surprised.

1 pic of shoulder area in chamber. Not relevant to this issue nor accuracy but still it's disappointing & hopefully not the norm.

Pictures of the go gauge used when this was assembled, might have been go +.001 at most. And a pic of where it is head spaced now No Go + .004 via 2 pieces of scotch tape.

Pictures of 1 x fired Hornady 108 in Bartlein barrel compared to 1 x fired Lapua in Rainier barrel in Headspace comparator. Both are deprimed.

Let me know your thoughts?

Thanks



On Mon, Jan 31, 2022 at 2:46 PM Rainier Arms <[email protected]> wrote:
Rainier Arms

Thank you for your order from Rainier Arms. You can check the status of your order by logging into your account. If you have questions about your order, you can email us at [email protected] or call us at 877-556-GUNS.

Your Invoice


Expedited Shipping - Based off of Business Days. - Ground (7-10 Business Days)

Items Qty Subtotal
Rainier Arms UltraMatch MOD2 6mm ARC Rifle Barrel - 22"
SKU: RAB-UM2-6ARC-22-R2-FF-SAT

Color
Satin
1 $400.00
UN12 Magazine - Issue 7 (NO PATCH)
SKU: UN12-7-PROMO
1 $0.00
Subtotal $400.00
Shipping & Handling $16.31
Tax $24.00
Grand Total $440.31
Thank you

 

[supercorndogs]

Mike S is who I dealt with.

Below are excerpts from my correspondence with them in reverse order.

As you can see I stressed they had a heat treat problem with the Tin coated extensions.

I did receive the replacement, but only have 40 rounds on it.

Mike,

Following up on this. Called last week on the 13th & spoke to someone. He said he’d been trying to head space a new barrel to the old bolt. Told him to give up as that bolt was just sent so you would have the full picture. He said A new barrel would ship Tuesday the 14th? Haven’t received any email or tracking. Has this shipped?

Thanks

Mike,

Thank you for the reply.
I would prefer you just replace the barrel. If the replacement barrel extension can easily be verified for heat treat by your shop that would be fantastic.
The barrel was shipped today using your label. You should receive it Tuesday 3/7. Tracking #

I did include the Maxim bolt that was run with the barrel. If possible I'd like the bolt returned with the new barrel. Ejector + spring & extractor were tuned and I'd like to recycle them for spares.

Not sure if your shop has the ability to perform a Rockwell test on the extension, but I would suggest doing so. It's a very high probability this was the result of improper heat treat by your extension or heat treat vendor.

Build specs below for ref.
VLTOR Fusion F-15 monolithic upper, receiver face trued, extension thermal fitted with 1 full wrap of SS .001 shim stock
Odin works adj gas block & + 2" gas tube.
Rubber City light weight bolt carrier, FP, Cam pin
Maxim type 2 6.5 Grendel bolt
JP silent capture buffer system std weight + standard spring
Magpul PRS gen 3 stock + spacer for silent capture.
JL billet ambi lower
Trigger Tech single stage & ambi selector

Gas block was running pretty close to the center of adjustment range.
The ejection pattern was 4:00
BCG over travel was checked and good.


Attn: Mike
Total round count on barrel is 446. FWIW the receiver face was trued and the barrel was installed with 1 full wrap of .001 shim stock. Lug contact was even & I always run lube on carrier and lugs. When new head space with new Maxim bolt was Go plus at most .001. Now it's go plus .0013

Per our conversation please see attached pictures of the barrel extension. The pictures are in the following counter clockwise order looking from the back.
3, 1:30 (extractor lug), 12, 10:30, 9, 7:30 (might have to stare at this one for a minute), 6, 4:30.

1 picture of 12 oclock lug on Bartlein with 100 rounds on it for reference.

Pictures of the bolt lugs & top.
Back of extension showing metal displaced back on bottom 3 lugs

I think the extension was either improperly heat treated or Tin coated without heat treat. Hopefully you didn't get a big batch of the same. I have a lot of AR's and have never seen this happen before.It was gaining almost .003 HS per 100 rounds. I do not trust this to continue running it. I spoke with one gentleman who's broken 3 bolts each @ about 1000 rounds. Each time a new bolt head spaced to the barrel i.e. no extension wear. He was also running Varget which IMO is too fast a powder for ARC so I'm not that surprised.

1 pic of shoulder area in chamber. Not relevant to this issue nor accuracy but still it's disappointing & hopefully not the norm.

Pictures of the go gauge used when this was assembled, might have been go +.001 at most. And a pic of where it is head spaced now No Go + .004 via 2 pieces of scotch tape.

Pictures of 1 x fired Hornady 108 in Bartlein barrel compared to 1 x fired Lapua in Rainier barrel in Headspace comparator. Both are deprimed.

Let me know your thoughts?

Thanks



On Mon, Jan 31, 2022 at 2:46 PM Rainier Arms <[email protected]> wrote:
Rainier Arms

Thank you for your order from Rainier Arms. You can check the status of your order by logging into your account. If you have questions about your order, you can email us at [email protected] or call us at 877-556-GUNS.

Your Invoice


Expedited Shipping - Based off of Business Days. - Ground (7-10 Business Days)

Items Qty Subtotal
Rainier Arms UltraMatch MOD2 6mm ARC Rifle Barrel - 22"
SKU: RAB-UM2-6ARC-22-R2-FF-SAT

Color
Satin
1 $400.00
UN12 Magazine - Issue 7 (NO PATCH)
SKU: UN12-7-PROMO
1 $0.00
Subtotal $400.00
Shipping & Handling $16.31
Tax $24.00
Grand Total $440.31
Thank you

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I can already see material bubbling up on my feed ramps at 20rds with my replacement. It looks just like yours.
They are stressing that it is entirely unlikely they have two bad extentions from diffrent batches. And asking what ammo i used and telling me improper spring or buffer is the only thing they can think of of that would cause this.

 

[357Max]

I can already see material bubbling up on my feed ramps at 20rds with my replacement. It looks just like yours.
They are stressing that it is entirely unlikely they have two bad extentions from diffrent batches. And asking what ammo i used and telling me improper spring or buffer is the only thing they can think of of that would cause this.

Their feed ramps are to big for a 6mm & I’m betting they never Rockwell tested as I suggested.

If they can’t tell you how hard the extension is then they’re wasting there time thinking about buffer springs.

You should break bolt lugs before setting back extension lugs.

 

[supercorndogs]

Their feed ramps are to big for a 6mm & I’m betting they never Rockwell tested as I suggested.

If they can’t tell you how hard the extension is then they’re wasting there time thinking about buffer springs.

You should break bolt lugs before setting back extension lugs.

That's what I told them about bolt lugs. I also told them I use the same buffer spring and lower for my 6.5 grendel. I also used a diffrent buffer and spring for the second barrel. I am pretty confident no one could reproduce this damage in 20 rounds on a proper barrel extention.

 

[supercorndogs]

They asked me for loads now they are pulling the no warrenty with handloads card. 25g of varget with a 90TGK 2500fps. I asked to be moved up the ladder. Top right corners of feed ramps raised again in 20 rounds. Second pick of good side for contrast. You can see the lug between the feed ramps is twisting. I can feel the imprint of the bolt lugs in the barrel extention.

 

[Cascade Hemi]

That isn't a handload issue or a buffer weight issue.

 

[supercorndogs]

Thanks @357Max. They told me I am the only one having this trouble with one of their barrels. Your pictures and input are going to be invaluable I think.

 

[bigjake83]

They asked me for loads now they are pulling the no warrenty with handloads card. 25g of varget with a 90TGK 2500fps. I asked to be moved up the ladder. Top right corners of feed ramps raised again in 20 rounds. Second pick of good side for contrast. You can see the lug between the feed ramps is twisting. I can feel the imprint of the bolt lugs in the barrel extention.

View attachment 8361330
View attachment 8361334

Where in the fuck does it State anywhere that hand loads void the 90-day return policy?

Get your money back from these clowns and move onto something better.

Send me a PM if your frustration has finally allowed for your budget to grow.

 

[supercorndogs]

I am way past 90 days after purchase.

 

[bigjake83]

Thanks @357Max. They told me I am the only one having this trouble with one of their barrels. Your pictures and input are going to be invaluable I think.

Yeah?.. Thats funny, Burris said the same thing to me.

 

[bigjake83]

I am way past 90 days after purchase.

Oh.. I thought this was the new replacement.

Does the rest of the barrel look good, Inside and out?

 

[supercorndogs]

This is the new replacement. I am just assuming they didn't restart the clock since my original purchase.

I got another email after asking to speak to a manager or someone who was knowledgeable. They said they are committed to sorting this out for me. They want the upper again and all my specs from my lower. I guess they must not have inspected anything when I sent it in the first time.

I don't want another barrel from them until they sort out this barrel extention thing. I bet there are a lot out there that look just like mine and haven't been noticed yet because the gun is still functioning fine. I bet most any factory ammo shooter is going to be well into the headspace danger zone before they notice.

 

[bigjake83]

This is the new replacement. I am just assuming they didn't restart the clock since my original purchase.

I got another email after asking to speak to a manager or someone who was knowledgeable. They said they are committed to sorting this out for me. They want the upper again and all my specs from my lower. I guess they must not have inspected anything when I sent it in the first time.

I don't want another barrel from them until they sort out this barrel extention thing. I bet there are a lot out there that look just like mine and haven't been noticed yet because the gun is still functioning fine. I bet most any factory ammo shooter is going to be well into the headspace danger zone before they notice.

If you do t get anywhere with this new "assessment" I can get you in touch with some one who can replace the barrel exstenion.

 

[FredHammer]

I understand a company having a filter of ask & answer to weed out frivolous claims, but when the issue rises above or beyond the initial screening of the issue they need to fucking own up. The behavior of a shit company is readily apparent when they do the typical dig heels in sand like they can do no wrong with their product, then blame the problem on something the customer did, then squirm out of a warranty with some bullshit "clause" still blaming the customer. Especially after customer provided detailed info and photo evidence of a problem. I will tell places like this that they've lost more money on future sales because they wanted to die on a hill for one sale. Fuck them.

 

[supercorndogs]

If you do t get anywhere with this new "assessment" I can get you in touch with some one who can replace the barrel exstenion.

I was wondwring about that as an option as well.

I thought about getting a cheap 6mm arc barrell, stick it in there and see if it gets damaged. I don't want to be dragging them through the mud if I am wrong. But if I am correct it means there may be quite a few unsafe barrels running around. My first barrel gained at least .01 in head space and I would suspect .015 in 400 rounds or so. My die set up was at 100 rounds the first time.

I kind of thought they would look at this and draw the same conclusions as me. Not give me horse shit about buffers and spring and the bolt running too fast.

I emailed optics planet a couple days ago to see if they will take back the rainer barrel. It looks like I bought it last March so its past the point of click on item and print return label.