Carbon Barrel cracked??

LRTalley

LRTalley

Private
Minuteman
Dec 1, 2017
13
4
Tennessee
#1
I have a Bartlein CF barrel chambered in 300 W.M.
Sent it to be put in a cryogenic chamber to relieve any existing stress in barrel, upon unboxing I found the carbon cracked completely through in 2 separate spots.
Also sent a Proof barrel chambered with same reamer to have the same process done and it looks the same as it did when I sent it off.
How big of an issue/problem is this and has anyone experienced the same before?
Thanks in advance.
 

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#7
Certainly been a long time since my materials engineering classes. But carbon fiber is fairly resistant to thermal change. Steel less so. Between 5 and 10 times less so. So as you cooled the barrel, the carbon fiber shrank linearly 5x to 10x less than the steel, and that pressure from the 2 shoulders of the barrel compressing inwards on the CF is likely what caused what looks like partial delamination.

Others with way more experience than me will likely chime in, but I’m honestly more surprised that the proof isn’t showing issues, I’d check it much more closely.

ETA: fixed some autocorrect
 
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#8
Metal contracted from being so cold and the carbon didn't? The 2 are bonded to each other so it caused the carbon to crack?

If the cracks are mostly cosmetic and it's still safe to shoot, I cant imagine it's gonna shoot well.
 
#9
Oh my. I think you will have a sad panda face…but curious what Frank says.

It’s implied, but confirm the Proof was CF?

Sorry,
ZY

Ps. A little surprised the company cryo’d these—and they didn’t tell you before shipping there was an issue. Where they a gun-related company?
 
#11
You just learned an expensive lesson. If you can, you should get a refund and get them to pay the cost of replacement barrels from whoever offered the cryogenic treatment for a carbon wrapped barrel. They should've told you it can't be done.

The carbon fiber matrix, commonly known as resin, is what failed (cracking and debonding).

Not worth the effort to try and salvage.
 
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#19
I was part of a project that involved wrapping Titanium spools in raw carbon and glass, the cure cycle would cause a disbond almost every time, regardless of ramp rates or cool down process, dissimilar materials are a bitch because of thermal growth rates not being equal.

It was an exhausting 7 months working on that project, ironically, we didn't experience the same failure rates with stainless or carbon steel spools, but the weights were deemed unacceptable.
 
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#21
So Bart uses a 3rd party company to wrap the turned down blanks. They're the worst finish of any carbon barrel I've personally put hands on. They're rough, splintered, the epoxy has voids(like you have here) Take a microfiber cloth and wipe down the barrel twisting with the direction of the carbon wound wrapp, it'll grab the loose fibers and stick em in ur hand, or grab fibers and stick the towell. I know 3 cerakote shops that only do the bart carbons with low temp air cure paint, as the standard oven temps bleed the resin out the shoulders of shank and muzzle. Also, the carbon will pull away from the shoulders at the ends at typical oven cure drying temps. I've had 4 Bartlein carbons, and the exterior finish on my first one was pretty decent, still some loose splintering fibers, but the last 3 were poor. HARD PASS for me moving forward.
 
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#22
4O6shootist said:
So Bart uses a 3rd party company to wrap the turned down blanks. They're the worst finish of any carbon barrel I've personally put hands on. They're rough, splintered, the epoxy has voids(like you have here) Take a microfiber cloth and wipe down the barrel twisting with the direction of the carbon wound wrapp, it'll grab the loose fibers and stick em in ur hand, or grab fibers and stick the towell. I know 3 cerakote shops that only do the bart carbons with low temp air cure paint, as the standard oven temps bleed the resin out the shoulders of shank and muzzle. Also, the carbon will pull away from the shoulders at the ends at typical oven cure drying temps. I've had 4 Bartlein carbons, and the exterior finish on my first one was pretty decent, still some loose splintering fibers, but the last 3 were poor. HARD PASS for me moving forward.
Click to expand...
Agree, the finish is total garbage. I handle mine very carefully cause I'm scared I'm gonna take a glass shard through the hand. I won't buy another one until they fix that.

Now I would never have cryo'd carbon barrels... but I'm not surprised to see the proof survive it and the bartlien fall apart. The quality of the carbon work isn't even comparable.
 
#23
To the OP…. Give us a call next week. I’m gone for the weekend now. I’ll talk to the carbon guys and see what we can do with it.

Yes… why did you have it cryo’d to begin with? The material is already heat treated and double stress relieved. Cryo for all I’ve seen does nothing for accuracy, cleaning or barrel life. That goes back to the quality of the barrel to begin with. I’ll say back in the day when we messed with cryo a lot… I seen one if not two barrels after they were shot and then had a cryo done to them didn’t shoot the same? It’s also not a cure all for barrel that doesn’t shoot. You can try it if you can get it done inexpensively cost wise but don’t get your hopes up.

Two the last two posts…. Way in the beginning to now the way it’s done is pretty different. Also shortly after starting it the carbon guys changed a couple of things and after seeing issues… we had a sit down about what was going on… changes where made and since then things have been pretty consistent. Also over the years I’ve seen issues with Proofs as well.

To me the cfw barrels… you want to save weight.. change the contour and skip the cf and save your money. If you like it because you think it looks cool… knock yourself out. It’s like fluting to me. It’s cosmetic. It does nothing for barrel life or accuracy. I also don’t like something different touching my barrel you have another variable to deal with if there is an issue.

Later, Frank
Bartlein Barrels
 
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#24
I have had 1 carbon barrel 6.5 cm and seen 2 others. I have never seen a carbon barrel shoot a 5 shot group under 1/2. I been told they can it's just I have never seen it. My barrel would shoot great 3 shot groups but never a 5 shot group. I try 7 different 6.5 bullets and had the same result. This is why they are great for hunting. I will say there was very little if any cold bore shift so that is good.
 
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#25
Frank, your last paragraph echoes what I've been saying to friends that want carbon barrels. Get a sporter wgt barrel and save the 500+$ over a carbon. Seems they are billed as for hunting, but so are shorter wgts. I've never needed more than 2rds in a hunting situation, so the extra stiffness of a fat carbon isn't gonna be too useful.

I too have shot a few carbon barrels of buddys. They would shoot really nice for 3ish shots, but the next 2 rds would open up and turn a cloverleaf hole into a 3/4" group. Consistently and with different handloads.
 
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#26
6brshooter said:
Frank, your last paragraph echoes what I've been saying to friends that want carbon barrels. Get a sporter wgt barrel and save the 500+$ over a carbon. Seems they are billed as for hunting, but so are shorter wgts. I've never needed more than 2rds in a hunting situation, so the extra stiffness of a fat carbon isn't gonna be too useful.

I too have shot a few carbon barrels of buddys. They would shoot really nice for 3ish shots, but the next 2 rds would open up and turn a cloverleaf hole into a 3/4" group. Consistently and with different handloads.
Click to expand...

It's not as bougie though 🙃
 
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#28
6brshooter said:
Frank, your last paragraph echoes what I've been saying to friends that want carbon barrels. Get a sporter wgt barrel and save the 500+$ over a carbon. Seems they are billed as for hunting, but so are shorter wgts. I've never needed more than 2rds in a hunting situation, so the extra stiffness of a fat carbon isn't gonna be too useful.

I too have shot a few carbon barrels of buddys. They would shoot really nice for 3ish shots, but the next 2 rds would open up and turn a cloverleaf hole into a 3/4" group. Consistently and with different handloads.
Click to expand...

I did a 20” .223 barrel with the lightest contour that I could put 5/8”x24 muzzle threads on, it came out to 55 oz which was a pound heavier than my 20” 7 PRC barrel.
 
#29
Evintos said:
. . . . . you should get a refund and get them to pay the cost of replacement barrels from whoever offered the cryogenic treatment for a carbon wrapped barrel. They should've told you it can't be done.
Click to expand...
I don't have a dog in this hunt but I would say that while the Cryo company could have warned the customer about CF, the vast majority of the responsibility should fall back to the customer.

Anybody that knows how to even pronounce Cryo likely knows what it entails.

Who is to say that the Cryo vendor hasn't done hundreds of CF wrapped barrels with no prior issues. Lots and Lots of variables at play there. The barrels were sent for a deep freeze cycle and that is exactly what the Cryo vendor provided.

Too many people wanting to be reimbursed for time and damages lost due to their own poor decisions.
 
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#30
Terry Cross said:
I don't have a dog in this hunt but I would say that while the Cryo company could have warned the customer about CF, the vast majority of the responsibility should fall back to the customer.

Anybody that knows how to even pronounce Cryo likely knows what it entails.

Who is to say that the Cryo vendor hasn't done hundreds of CF wrapped barrels with no prior issues. Lots and Lots of variables at play there. The barrels were sent for a deep freeze cycle and that is exactly what the Cryo vendor provided.

Too many people wanting to be reimbursed for time and damages lost due to their own poor decisions.
Click to expand...
If I take my truck to a mechanic, the mechanic says he can do the work that I want done and ends up damaging a part of my truck while "completing" said work, who's liable? If there's a liability waiver in place with fair warning that the process could damage the item, then I would agree that the responsibility falls upon the customer.

Carbon fiber/Matrix/Resin cracking and debonding under cryogenic temperatures is a known thing even with the inclusion of nano silica (or other nano particulates with low thermal expansion) filler in the resin. Science has been trying to overcome this issue for a long time for other industries.

A vendor that specializes in the process should've rejected the order. This seems more to me like backyard cryogenics with a vat of liquid nitrogen.
 
#31
Evintos said:
A vendor that specializes in the process should've rejected the order. This seems more to me like backyard cryogenics with a vat of liquid nitrogen.
Click to expand...
We can find examples to back up both circumstances.
Mechanics put lift kits on trucks ALL THE TIME knowing that 90% of those trucks are going to prematurely blow out ball joints., etc. etc..

Don't get me wrong. I think they should have rejected it too. I just don't think they are more responsible than the person sending such parts in to begin with.
 
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#32
GIXXER2000 said:
I have had 1 carbon barrel 6.5 cm and seen 2 others. I have never seen a carbon barrel shoot a 5 shot group under 1/2. I been told they can it's just I have never seen it. My barrel would shoot great 3 shot groups but never a 5 shot group. I try 7 different 6.5 bullets and had the same result. This is why they are great for hunting. I will say there was very little if any cold bore shift so that is good.
Click to expand...
My MOBB Bartlein CF done by Mission Specific doesn't have any issues putting bullets in the same hole. Great BBL.

The Proof and PVA BBLs I've had all do great as well, though the Proof's are all slower.
 
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#33
@LRTalley - if I was you, I would go and talk to the cryo company now. It was their service that ultimately ruined your barrel, while it was in their care. They need to take care of you. IMO, its their responsibility to make this right. That barrel didn't arrive to them in that condition, so for it to come back in worse condition is completely on them.

Yes, it was foolish of you to take a high quality barrel like a Bartlein and have it cryo'ed. But we all do foolish things from time to time. Anyone who claims that they haven't done something stupid in here is lying.

Consider this a lesson learned, and hopefully not an expensive one.
 
#35
Just my view and not a comment on anyone's particular love or hate of CF barrels...but I too don't see the value.

If on a PRS barricade/BR/bench and prone target gun who cares about the weight and a heavy steel barrel does, to my uninformed mind, offer a greater heat sink that a slimmed down steel barrel wrapped in CF.

Now...I don't climb 6k' mountains to hunt....I'm not a WY or similar mountain hunter in any respect of the term....but in a typical hunting situation (not varmint eradication) you are talking what...maybe two shots max. So, if weight is a concern, just get a slimmer steel barrel. and even for .338, TBAC Magnus comes with 5/8" x 24 and even 1/2" x 28 (if I read TBAC's spec's right)

They may be a good option for off-hand HP Silhouette type shooting where you will have strings of fire and weight is an issue.

This is just my thinking on the subject...but most people laugh hysterically at my thinking in general! haha
 
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#37
I spent a long time calculating the diameters at different lengths for steel barrels to meet the minimum diameter to thread for a supressor. Decide how much weight I needed to add in order to make the diameter requirement. Then decide how much weight I could pull back out with fluting.

Carbon Fiber barrels have their place.

I have noticed that the finish on my proof's is different then the finish on my bartlein. Is one better then the other? I have no idea. They are both more accurate then I am.
 
#39
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#40
Baron23 said:
It is now.


As for 1/2”, I mentioned only because it’s part of their offering.

5/8’s should leave you about .145 of barrel thickness at the muzzle threads. Now, I have no argument if you still feel that’s too thin. Your gun, you choices. Right?

Cheers
Click to expand...

5/8-24 leaves .1125" wall thickness. Wall thickness is calculated from the minor OD, not major OD.
 
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#42
Having a carbon fiber barrel takes a couple of pounds off and after going from one barricade to another during the ridge class, that gets tiring.

I for one haven’t noticed it be significant issues… and if you have a rifle that’s gonna be good for 2500 rounds. It’s probably worth doing.

I will say that the six Creedmoor I picked up in an MTU barrel is freaking heavy… but I am wondering given just how much those things wear out throats if there’s an advantage to having an MTU.
 
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#43
GBMaryland said:
Having a carbon fiber barrel takes a couple of pounds off and after going from one barricade to another during the ridge class, that gets tiring.

I for one haven’t noticed it be significant issues… and if you have a rifle that’s gonna be good for 2500 rounds. It’s probably worth doing.

I will say that the six Creedmoor I picked up in an MTU barrel is freaking heavy… but I am wondering given just how much those things wear out throats if there’s an advantage to having an MTU.
Click to expand...
Why would throat wear have anything to do with barrel contour? Maybe you can clarify what you mean.
 
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#45
Both actually… it’s a bigger heat sink, so you’re five or 10 strings won’t heat the whole thing up quite as much. Probably reducing wear a little bit…

Then, you can have it set back as well… PVA is right around the corner and they could easily clean that up for a couple hundred dollars.
 
#46
kthomas said:
@LRTalley - if I was you, I would go and talk to the cryo company now. It was their service that ultimately ruined your barrel, while it was in their care. They need to take care of you. IMO, its their responsibility to make this right. That barrel didn't arrive to them in that condition, so for it to come back in worse condition is completely on them.

Yes, it was foolish of you to take a high quality barrel like a Bartlein and have it cryo'ed. But we all do foolish things from time to time. Anyone who claims that they haven't done something stupid in here is lying.

Consider this a lesson learned, and hopefully not an expensive one.
Click to expand...
Na. Dumb dumb asked for a service and they did it. They gave the customer exactly what he asked for. Consider it a lesson in doing due dillegence.
 
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#47
Materials used in barrels have different thermal expansion and contraction properties, the more dissimilar, the greater those rates are. If cryo is the end all be all, why not do the barreled actions?
 
#48
GBMaryland said:
Having a carbon fiber barrel takes a couple of pounds off and after going from one barricade to another during the ridge class, that gets tiring.

I for one haven’t noticed it be significant issues… and if you have a rifle that’s gonna be good for 2500 rounds. It’s probably worth doing.

I will say that the six Creedmoor I picked up in an MTU barrel is freaking heavy… but I am wondering given just how much those things wear out throats if there’s an advantage to having an MTU.
Click to expand...
I have a 26" light palma steel, it's the same weight as a benchmark sendero carbon, shoots better too. If a person wants lighter weight, run a light palma, still able to cut 5/8x24 for a muzzle device.
 
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