Barrel Pitting

[FeMan]

My 284 has 2500 rounds down the barrel so it is time to pitch it. I shot it in a two-day tactical match a couple weeks ago for its last outing. It was very hot and the barrel got hot enough that I blew up two ELDMs even running the barrel cooler. It still shot very well and got me on the platform but the lost rounds were concerning, although not entirely unexpected with ELDMs.

I decided to clean the barrel one last time and scope it for giggles before I spun the new one on. I found this area that looks like pitting 12-inches from the breach. I am not sure what to make of it. It looks like chemical pitting. Does anyone have any thoughts on this blemish and the likely cause? If I need to change my cleaning Id like to know. Between my Dasher, 6.5x47 and 284 I've gone through over a dozen barrels and never seen this before.

I use Boretech C4 and Wipeout for cleaning. I flush with alcohol when done and then run two Kroil patches down the bore. I do let these soak a while in between patching once I lose most of the color. I also finish with a series of 10 or so stroked with a bronze brush once the chemicals yield nothing.

Any thoughts or words of wisdom are appreciated. Thanks!

 

[AllenOne1]

If you got 2500 good rounds out of your barrel I wouldn't change anything. I don't have any ideas on what caused issue you are seeing, are you sure it hasn't been there all the time?

 

[Terry_M]

Did you miss a SS pin when cleaning your brass?

As stated already, if you got 2500 rounds barrel life from it then what you're doing is working.

 

[billlarson]

Not sure what that scrape is.However if it was'nt there before and you clean with ss pins,I have saw 2 seperate accounts of pins in chambers.Must be common to send them down the barrel without knowing...
Bill

 

[spclark]

You shoot moly'd bullets maybe?

Don't flame me, I'm just askin'!

 

[FeMan]

No steel pins for cleaning and no moly. Naked bullets and corn cob.

I agree the barrel is fully depreciated. I am not sure how long this has been there. It wasn’t there new though. At least I never saw it before. I have not scoped the barrel in a while though.

 

[ronsatspokane]

You are correct about the ELDM's. I was getting about a 5 percent failure rate with the 147 ELD's in a 6.5 PRC. Called Hornady and told them. They asked me the lot number and said they'd get back to me. Never heard a word. Went back to Burgers and never had another problem. I know where you can get about 300 of those pieces of shite real cheap.

 

[Specimen]

My 284 has 2500 rounds down the barrel so it is time to pitch it. I shot it in a two-day tactical match a couple weeks ago for its last outing. It was very hot and the barrel got hot enough that I blew up two ELDMs even running the barrel cooler. It still shot very well and got me on the platform but the lost rounds were concerning, although not entirely unexpected with ELDMs.

I decided to clean the barrel one last time and scope it for giggles before I spun the new one on. I found this area that looks like pitting 12-inches from the breach. I am not sure what to make of it. It looks like chemical pitting. Does anyone have any thoughts on this blemish and the likely cause? If I need to change my cleaning Id like to know. Between my Dasher, 6.5x47 and 284 I've gone through over a dozen barrels and never seen this before.

I use Boretech C4 and Wipeout for cleaning. I flush with alcohol when done and then run two Kroil patches down the bore. I do let these soak a while in between patching once I lose most of the color. I also finish with a series of 10 or so stroked with a bronze brush once the chemicals yield nothing.

Any thoughts or words of wisdom are appreciated. Thanks!View attachment 1190643

If you missed a stainless pin, the cartridge brass would have been torn up. Did you see any torn-up brass?

 

[FeMan]

If you missed a stainless pin, the cartridge brass would have been torn up. Did you see any torn-up brass?

I don't use stainless pins.

 

[Sandstorm]

I have seen numerous ELDM.s not reach a 1000 yd F-Class target. I was scoring
for a fellow shooter and it was X, X. 10 , X .....what puff....try another /..puff
yea they will do that and cost you a Match in the process.
I will never use them,
its 180 flippin Bergers for me or nothing...and I never got more n 1800 rounds out of mine.
Ya done well FeMan

 

[RegionRat]

To be honest, in my experience I had to saw those sections out and cut them open to do a post-mortem on barrel steel.

Before I went that far, I would dry patch the area again to make sure it wasn't some combination of other artifacts that fool me into thinking it was the steel when it was foreign.

A static 2D view is always a little risky to interpret, but I know you have seen it while moving the borescope so your brain can fill in the 3D information as to positive material versus missing material.

Once opened up and in the labs, it was easy with FTIR to identify organics laying on there, then SEM-EDX to identify the balance of everything elemental. If there was anything like an inclusion or contamination in the steel to begin with, versus damage to otherwise good steel, we would be able to tell.

12" away from the chamber is sort of a gray zone. Things at that distance in a match gun tend to fall into a different category than the ones within the first few inches due to the differences in pressure/speed/heat etc.

Since you asked for a preemptive guess, I don't think it was due to chemical attack due to your cleaning, but I cannot rule out cleaning damage or original material defect or inclusion. Nothing wrong with alcohol, but be careful with it to avoid getting water from the alcohol or condensation from the alcohol. As long as you came back soon after with Kroil or something like it, the alcohol isn't anything to worry about.

Like the others have already said, I also think that if you got 2500 good shots out of this, you did good.

 

[Ray123]

In Competion? Replace the barrel...its not stainless steel pins.
2500 rds is what you got, with the load and pressure you shoot it at...the barrel is toast. And will only get worse, replacement is the fix...like a worn tire.

 

[JMayo]

To get the barrel that shiny you must really work it over.
That's so unnecessary imo.
I've seen the fire crack break up on several barrels. I let them stay filled.

 

[FeMan]

Good point on the alcohol Region Rat. I never thought about that.

Thanks to everyone for their comments.

 

[D-4297]

Only taking a WAG ; without the barrel in front of me , but it gives all the general appearance of plain old-fashion lamination separation , from the long term heating and cooling cycles . As other have said ; 2400 rounds ? Keep doing what you're doing . It seems to be working for you .

 

[Ned Ludd]

It's very difficult to say anything meaningful from a single image. It could be separation of a surface layer of metal, but it could be a lot of other things, too. I've even observed pieces of lint from cotton patches in a bore that looked quite ominous until I figured out what they actually were. At 2500 fired rounds in a barrel you're about to toss, I wouldn't be too concerned about it. If you see something similar show up in the next barrel at something like 800-1000 rounds, then I might think differently about it.

FWIW - the C4 carbon cleaner you're using is an aqueous solution (i.e. dissolved in water), and from the melting point/boiling point, the Wipeout may be as well (can't tell from the MSDS). Water is generally not harmful to a barrel as long as it's gone before the end of the cleaning process and patches of some kind of oil or lubricant/protectant that are not water based get passed through prior to dry patches at the end of the process. A number of commonly-used cleaning agents such as C4 and Cu2+ that are generally considered to be very benign to the bore are water-based.