Borescope pics- anybody guess what this is?

[jpretle]

Dusty, moly residue that has absorbed moisture???

 

[Prose]

If it’s occurring under a layer of copper, would it be considered erosion or corrosion? I think of erosion as being mechanically induced (sliding contact between bullet/bore and impingement of hot gasses), and corrosion as a chemical process (galvanic reaction between dissimilar metals?). Not meaning to be “picky”, just trying to understand the phenomenon!

I called it oxidized corrosion, or wormies

 

[Downhill]

I am in Pipeline repair and that looks amazingly similar to the damage caused by an amoeba like organism found in gas wells. It will attach itself to the steel of the pipeline usually in areas where condensate collects. There it forms a colony like structure and actually feeds on the steel. The result is a leaking pipeline or possible rupture. Same kind of wormlike lines.

 

[Delfuego]

Some of you guys thats been around a while will recognize this damage. Anybody want to guess?View attachment 1153715

That's the Coronavirus Dusty, better go see a doctor...

 

[skeeljc]

So it is some kind of chemical corrosion? Just what exactly is the chemical process that caused the corrosion (chemical erosion of the steel)?

 

[dmoran]

If it’s occurring under a layer of copper, would it be considered erosion or corrosion? I think of erosion as being mechanically induced (sliding contact between bullet/bore and impingement of hot gasses), and corrosion as a chemical process (galvanic reaction between dissimilar metals?). Not meaning to be “picky”, just trying to understand the phenomenon!

Oxidation of fouling, being the cause for the erosion/corrosion, in a form of pitting that can look etched, is how I will define it.

 

[flatlander]

There's no question that a lot of the hype about the advantages of moly coating bullets that was published in magazines like Precision Shooting back in the early '90s was just that - hype. I bought into it to the extent that I moly-coated & waxed nearly every bullet I bought for 20yrs or so. But I never bought completely into the hype about not cleaning. I did try to 'get by' by cleaning with Kroil & nylon brushes in one of my AR15 service rifle Kriegers, but that came to a screeching halt after borrowing a good friend's Hawkeye borescope while trying to clean that barrel. After the borescope revealed how much carbon & copper fouling was left after doing such a mild (in effect - useless) cleaning with Kroil, it took me a few days of applying Shooters Choice & brushing with bronze brushes to get all that crap out of the bore. IIRC, I wound up using IOSSO bore paste to finally get the bore clean, and thankfully, I didn't find any of this sort of damage in that bbl after I finally did get it clean. I don't blame such corrosion on moly - rather on shooters buying into not needing to clean.

Yes, a lot of guys poke fun at how much $$$ buying a bore scope has cost them, but from my 22RF bbls to collectible antique Winchesters, I use my Hawkeye to assess the bore conditions of all my rifles. And I also use it to examine chambers as I'm reaming them in new bbl blanks on the lathe. Wouldn't be without it, but would like to figure out whether one of the less expensive models would work better for photographing bore conditions.

 

[Monte F]

Does it still shoot? that is what matters most. I have seen the same in my F-TR barrel since getting the Teslong. Shooting Master/High Master scores at 1000, so I guess it isn't hurting things.
Those bore worms came back on the Shuttle, alien worms?

 

[dmoran]

@flatlander
I like the Teslong better for most examination scenario's.
And there so inexpensive, I highly recommend them.

 

[andrew l]

Unless you checked before you ever fired a shot, it may not be from you. I have seen pitting and such in NEW factory barrels from Savage, T/C, and Marlin.

I've also seen this in brand new stainless cut rifled blanks.

 

[Ringostar]

That's the Coronavirus Dusty, better go see a doctor...

I heard that lymes disease goes good with corona virus!

 

[Drop Port]

It's also contagious but can only be detected with a bore scope. The cure is harsh you must thoroughly destroy and dispose of your bore scope and quarantine your barrels by not letting them come within 10' of a bore scope.

 

[AccelR8]

....changed my mind about collecting old deer rifles . Those shiny on the outside gems sure can be ugly on the inside.

Same thing with people, that's why I've stopped collecting them!

 

[Texas10]

^ yes its from moly and not cleaning since he heard you dont have to clean if you use moly

Any idea what is the chemical reaction taking place and how it forms tracks/trails?

Looks a lot like the copper related corrosion Dmoran posted.

 

[Dusty Stevens]

Any idea what is the chemical reaction taking place and how it forms tracks/trails?

Looks a lot like the copper related corrosion Dmoran posted.

No im not sure

 

[Texas10]

I am in Pipeline repair and that looks amazingly similar to the damage caused by an amoeba like organism found in gas wells. It will attach itself to the steel of the pipeline usually in areas where condensate collects. There it forms a colony like structure and actually feeds on the steel. The result is a leaking pipeline or possible rupture. Same kind of wormlike lines.

I thought you were just BS-ing but no, it's call Microbiologically Influenced Corrosion or MIC.
https://corrosion-doctors.org/Pipeline/Internal-corrosion.htm

Also referred to in the infamous Steel Report when discussing possibility of Uric acid induced destruction/corrosion (of brain cells) in certain individuals.

OK, that Steel report part was indeed BS but just couldn't resist the temptation.

 

[Texas10]

No im not sure

Some research on Molybdenum Disulfide and I find that it is both a dry lubricant and corrosion inhibitor. Interesting because what you've seem to find is corrosion in stainless steel where moly had been used.

However, this article http://www.cor-pro.com/corrosion-protection-services/coatings/molybdenum-disulfide/ seems to suggest that those properties are present when moly is mixed with certain resins, binder and water soluble sulfides to improve it's corrosion inhibitor properties.

And this brings to mind the question of whether all moly is the same when it comes to bullet lubes. Are we using the best moly? Or is the less expensive moly also less able to inhibit corrosion?

Also brought to mind is the question of whether the barrel you inspected as was ever shot with copper jacketed bullets and what, if any, possible interaction copper and moly can have on a SS barrel, especially when combined with humidity or cleaning chemicals.

 

[Dusty Stevens]

Some research on Molybdenum Disulfide and I find that it is both a dry lubricant and corrosion inhibitor. Interesting because what you've seem to find is corrosion in stainless steel where moly had been used.

However, this article http://www.cor-pro.com/corrosion-protection-services/coatings/molybdenum-disulfide/ seems to suggest that those properties are present when moly is mixed with certain resins, binder and water soluble sulfides to improve it's corrosion inhibitor properties.

And this brings to mind the question of whether all moly is the same when it comes to bullet lubes. Are we using the best moly? Or is the less expensive moly also less able to inhibit corrosion?

Also brought to mind is the question of whether the barrel you inspected as was ever shot with copper jacketed bullets and what, if any, possible interaction copper and moly can have on a SS barrel, especially when combined with humidity or cleaning chemicals.

It has 14rds on it over 10 or so yrs and every single one was moly. It has never been cleaned and did not have this in there when new

 

[skeeljc]

Some of you guys thats been around a while will recognize this damage. Anybody want to guess?View attachment 1153715View attachment 1153716View attachment 1153717

So the final answer is it is some kind of corrosion that resulted from the lack of proper cleaning?

Interesting question: Would the frequent use of a borescope have prevented this damage?

 

[Dusty Stevens]

So the final answer is it is some kind of corrosion that resulted from the lack of proper cleaning?

Interesting question: Would the frequent use of a borescope have prevented this damage?

No a borescope has nothing to do with it. This particular guy doesnt own a cleaning rod. This is a kids hunting rifle. The frequent use of non moly bullets would have just left it dirty. The moly combined with humidity causes some kind of corrosion thats over my head but discovered many years ago