Barrel Bore Cleaning. Howa Rust.

[dirtjay]

Gday.
I have a recurring corrosion issue on a new Howa 223
It’s a heavy barrel, and only shot about 30 rounds since new.
The problem is I’m finding rust in the bore every week now.
I have 2 other Howas that don’t have this problem at all.
The 223 sits in a safe with 2 other rifles and they do not do what this one does.
Cleaned before sighting in, then oiled and sat in the safe for 3 weeks. Fired PPU factory ammo.
Only first noticed the build up on a trip out west, when a bore snake would not fit just prior to heading out.
Cleaned it out, brush,mop,oil, patched till clean.
The washout was a dark brown, I wondered if a mud wasp nest was in there.
Cleaned and oiled before put in safe when returned home.
2 weeks later I looked at it and the rust looking material was in the bore again. I oiled and brushed, mop, patched and solvent cleaned, then oil again.
1 week later (today) it’s back again.
I can’t understand how fast and how thick it gets.
The same dark brown washout continues.
It looks like a furry coating in the bore every week.

Anyone have any ideas what it could be???

I have a bore scope on its way.
But having shot it only 30 times, I don’t know what’s going on in the bore.

Would love to hear from others that have seen similar.

Cheers

[Damo300]

Id be returning that to the shop.
That does not look good at all, and to happen so quickly.

You're not using that bore cleaning solution are you?

[bigrich]

Gday.
I have a recurring corrosion issue on a new Howa 223
It’s a heavy barrel, and only shot about 30 rounds since new.
The problem is I’m finding rust in the bore every week now.
I have 2 other Howas that don’t have this problem at all.
The 223 sits in a safe with 2 other rifles and they do not do what this one does.
Cleaned before sighting in, then oiled and sat in the safe for 3 weeks. Fired PPU factory ammo.
Only first noticed the build up on a trip out west, when a bore snake would not fit just prior to heading out.
Cleaned it out, brush,mop,oil, patched till clean.
The washout was a dark brown, I wondered if a mud wasp nest was in there.
Cleaned and oiled before put in safe when returned home.
2 weeks later I looked at it and the rust looking material was in the bore again. I oiled and brushed, mop, patched and solvent cleaned, then oil again.
1 week later (today) it’s back again.
I can’t understand how fast and how thick it gets.
The same dark brown washout continues.
It looks like a furry coating in the bore every week.

Anyone have any ideas what it could be???

I have a bore scope on its way.
But having shot it only 30 times, I don’t know what’s going on in the bore.

Would love to hear from others that have seen similar.

Cheers

that's freakin' nuts mate . i've never heard of anything like it . it comes on that quick too . i use shellite to clean any solvent i use for cleaning and let it dry out before oiling . it's almost like there's some sort of metal electrolysis going on . maybe they stuffed up with the metal used to make the barrel ? i'm at a complete loss to explain this . best of luck

[dirtjay]

Id be returning that to the shop.
That does not look good at all, and to happen so quickly.

You're not using that bore cleaning solution are you?

I have only used the bore cleaner a week ago, its the Hoppes one.
This Howa was bought from the big shop in Margate, and I'm not confident they would be interested in doing anything for me.
Its also nearly 2 hour drive for me to get there.

Has anyone had contact with Howa directly?
Would that be worth trying?

Cheers
Jay

[Wapiti]

Id be returning that to the shop.
That does not look good at all, and to happen so quickly.

You're not using that bore cleaning solution are you?

I have only used the bore cleaner a week ago, its the Hoppes one.
This Howa was bought from the big shop in Margate, and I'm not confident they would be interested in doing anything for me.
Its also nearly 2 hour drive for me to get there.

Has anyone had contact with Howa directly?
Would that be worth trying?

Cheers
Jay

Mate what did you use before that? Only cos you mention:

"The problem is I’m finding rust in the bore every week now."
"Cleaned before sighting in, then oiled and sat in the safe for 3 weeks."
"2 weeks later I looked at it and the rust looking material was in the bore again. I oiled and brushed, mop, patched and solvent cleaned, then oil again."
"1 week later (today) it’s back again."

Looks like this has been happening for quite awhile now when I look at all those bits above that you mention that are in order. Sort of like a timeline of your problem. I don't doubt that it's been going on longer than that?
You also say that you only used the Hoppes product a week ago. (highlighted in red above)

Mate what cleaning product did you use before that?

Mate, the problem is not with the shop, and your issue is very odd and every time I've heard of this either, it is with the product used or the procedure of the cleaning.
There is no carbon steel in the world that just self-destructs, only what chemical is put on it or the procedure used in caring for it after that.

Are your other firearms sitting next to it using the same bore products, procedures and made of carbon steel?
Now, some steels do rust more readily than others when exposed to salts, moisture and air - are the other firearms Howas or other brands?

On Howas, their stainless steel used rusts very quickly just from being exposed to air when not coated with oil, when compared to say, Ruger 77's stainless, you could piss on them every day and leave them in the rain and you couldn't induce rust.

[Damo300]

Id be returning that to the shop.
That does not look good at all, and to happen so quickly.

You're not using that bore cleaning solution are you?

I have only used the bore cleaner a week ago, its the Hoppes one.
This Howa was bought from the big shop in Margate, and I'm not confident they would be interested in doing anything for me.
Its also nearly 2 hour drive for me to get there.

Has anyone had contact with Howa directly?
Would that be worth trying?

Cheers
Jay

Highly unlikely the Hoppe's is the issue.
SDS reveals nothing out of the ordinary.

https://assets.unilogcorp.com/187/ITEM/DOC/HOPPES_102274354_SDS.pdf

Can see the proprietary items listed but that's their secrete sauce, and I'm pretty sure non toxic therefore identity can be protected.

What was used on the first clean?

The fact you have 2 other rifles of the same breed sitting there, which I am going to assume have been cared for the same way, with the same ingredients, one can assume it's something isolated to this rifle.

And the shop won't help you with a new rifle?
I'd be in there demanding it be sent back to howa, or find a shop that will help you.

There are plenty of options if you cannot get help, but they're gonna cost you.

[Wm.Traynor]

dirtjay,
I am going to stick my neck out and say that I have never seen anything like your muzzle-pic.
1) I can't see any rifling
2) What I can see is something that looks like tiny golden particles

Not trying to be a S A but happy to be corrected (wouldn't be the first time).

[dirtjay]

Id be returning that to the shop.
That does not look good at all, and to happen so quickly.

You're not using that bore cleaning solution are you?

I have only used the bore cleaner a week ago, its the Hoppes one.
This Howa was bought from the big shop in Margate, and I'm not confident they would be interested in doing anything for me.
Its also nearly 2 hour drive for me to get there.

Has anyone had contact with Howa directly?
Would that be worth trying?

Cheers
Jay

Mate what did you use before that? Only cos you mention:

"The problem is I’m finding rust in the bore every week now."
"Cleaned before sighting in, then oiled and sat in the safe for 3 weeks."
"2 weeks later I looked at it and the rust looking material was in the bore again. I oiled and brushed, mop, patched and solvent cleaned, then oil again."
"1 week later (today) it’s back again."

Looks like this has been happening for quite awhile now when I look at all those bits above that you mention that are in order. Sort of like a timeline of your problem. I don't doubt that it's been going on longer than that?
You also say that you only used the Hoppes product a week ago. (highlighted in red above)

Mate what cleaning product did you use before that?

Mate, the problem is not with the shop, and your issue is very odd and every time I've heard of this either, it is with the product used or the procedure of the cleaning.
There is no carbon steel in the world that just self-destructs, only what chemical is put on it or the procedure used in caring for it after that.

Are your other firearms sitting next to it using the same bore products, procedures and made of carbon steel?
Now, some steels do rust more readily than others when exposed to salts, moisture and air - are the other firearms Howas or other brands?

On Howas, their stainless steel used rusts very quickly just from being exposed to air when not coated with oil, when compared to say, Ruger 77's stainless, you could piss on them every day and leave them in the rain and you couldn't induce rust.

Gday Wapiti,

We've spoken on the phone previously, maybe a couple years ago.
Just to answer your questions.
I have used G96 for cleaning all and other rifles, and all have had the same process that has was applied to this 223.
I only tried the bore cleaner to see if it would rid this issue, it did not.
I agree, I also believe this has been going on longer than I've known. I've had the rifle 5 months, brand new.
Now it has been documented became a concern at the last trip out west, and I am keeping an eye on it, along with trialing different techniques for remedy.
With all my previous cleaning techniques and procedures, I would not have expected this to happen as it hasn't happened with the other rifles.
Yes, the other two Howas are in the same safe, same steel, none of them are stainless steel.

I had a response from the big shop in Margate, and the advice was to block the bore, and see if it returns.
So i will be trying that for the next week.

cheers
Jay

[dirtjay]

dirtjay,
I am going to stick my neck out and say that I have never seen anything like your muzzle-pic.
1) I can't see any rifling
2) What I can see is something that looks like tiny golden particles

Not trying to be a S A but happy to be corrected (wouldn't be the first time).

Thanks mate,
I'm not going to correct you, I wish it was gold particles.
It patches out more brown than rusty red

[dirtjay]

Gday.
I have a recurring corrosion issue on a new Howa 223
It’s a heavy barrel, and only shot about 30 rounds since new.
The problem is I’m finding rust in the bore every week now.
I have 2 other Howas that don’t have this problem at all.
The 223 sits in a safe with 2 other rifles and they do not do what this one does.
Cleaned before sighting in, then oiled and sat in the safe for 3 weeks. Fired PPU factory ammo.
Only first noticed the build up on a trip out west, when a bore snake would not fit just prior to heading out.
Cleaned it out, brush,mop,oil, patched till clean.
The washout was a dark brown, I wondered if a mud wasp nest was in there.
Cleaned and oiled before put in safe when returned home.
2 weeks later I looked at it and the rust looking material was in the bore again. I oiled and brushed, mop, patched and solvent cleaned, then oil again.
1 week later (today) it’s back again.
I can’t understand how fast and how thick it gets.
The same dark brown washout continues.
It looks like a furry coating in the bore every week.

Anyone have any ideas what it could be???

I have a bore scope on its way.
But having shot it only 30 times, I don’t know what’s going on in the bore.

Would love to hear from others that have seen similar.

Cheers

that's freakin' nuts mate . i've never heard of anything like it . it comes on that quick too . i use shellite to clean any solvent i use for cleaning and let it dry out before oiling . it's almost like there's some sort of metal electrolysis going on . maybe they stuffed up with the metal used to make the barrel ? i'm at a complete loss to explain this . best of luck

Yep its nuts alright, I've never seen anything like it also.
I also think there is some sort of chemical reaction going on in there, as the chamber itself is still clean as a whistle.
All good mate, i will persist with getting some answers, and keeping track of what is happening.
It would be great if someone has seen this before, and says yep, do this and its gone.
I am somewhat concerned for the barrel now and what damage may have been done.
Hopefully the borescope arrives next week and I can check it out.

Cheers
Jay

[dirtjay]

Id be returning that to the shop.
That does not look good at all, and to happen so quickly.

You're not using that bore cleaning solution are you?

I have only used the bore cleaner a week ago, its the Hoppes one.
This Howa was bought from the big shop in Margate, and I'm not confident they would be interested in doing anything for me.
Its also nearly 2 hour drive for me to get there.

Has anyone had contact with Howa directly?
Would that be worth trying?

Cheers
Jay

Highly unlikely the Hoppe's is the issue.
SDS reveals nothing out of the ordinary.

https://assets.unilogcorp.com/187/ITEM/DOC/HOPPES_102274354_SDS.pdf

Can see the proprietary items listed but that's their secrete sauce, and I'm pretty sure non toxic therefore identity can be protected.

What was used on the first clean?

The fact you have 2 other rifles of the same breed sitting there, which I am going to assume have been cared for the same way, with the same ingredients, one can assume it's something isolated to this rifle.

And the shop won't help you with a new rifle?
I'd be in there demanding it be sent back to howa, or find a shop that will help you.

There are plenty of options if you cannot get help, but they're gonna cost you.

HAHA i would like to demand a new replacement, but I don't expect that approach would work in that shop.
They actually advised me to plug the bore and see if the substance returns, so thats what ill do for now.
I'll do the right thing and see what happens after another week

Cheers
Jay

[tuknal]

i had the exact same thing happen same rifle same calibre ,,i took it back to the dealer and was given a new one,
take it back and tell them you want a new one
i was told it was because the way i stored it ,,but i had 3 other stainless and 3 other blued rifles sitting in the same cabinet with no issues
dig your heals in,, stainless shouldnt rust like that in any normal circumstances
mine started in the chamber/breech area ,,
ive seen stainless rust from using grinding discs that were used on metals first ,,but i doubt youve been grinding near it
im wondering if the same tooling is being used on steel and stainless at the factory maybe

[Die Judicii]

Mate,,,, I have 3 Howas, and love em to death.
Your post sent me straight to the 2 of them that only get used occasionally,, to check them.
They are both in excellent condition and the same as they were the last time I checked.

Just by looking at your posted pic,,, I would never even attempt to put a single round down that barrel.
It looks like an old and decayed sewer pipe.

I would advise you pack it up, (with your other Howa's,, and make the 2hr drive with them, to show the "store" in person.
There would have to be (surely) a definite manufacture issue with that one barrel in particular.

[dirtjay]

i had the exact same thing happen same rifle same calibre ,,i took it back to the dealer and was given a new one,
take it back and tell them you want a new one
i was told it was because the way i stored it ,,but i had 3 other stainless and 3 other blued rifles sitting in the same cabinet with no issues
dig your heals in,, stainless shouldnt rust like that in any normal circumstances
mine started in the chamber/breech area ,,
ive seen stainless rust from using grinding discs that were used on metals first ,,but i doubt youve been grinding near it
im wondering if the same tooling is being used on steel and stainless at the factory maybe

Appreciate your reply mate.
Unfortunately, I'm a little relieved that it has happened elsewhere with the same brand and calibre.
Looks like i might have to take a day off work and head up there with them all.

Cheers
Jay

[dirtjay]

Mate,,,, I have 3 Howas, and love em to death.
Your post sent me straight to the 2 of them that only get used occasionally,, to check them.
They are both in excellent condition and the same as they were the last time I checked.

Just by looking at your posted pic,,, I would never even attempt to put a single round down that barrel.
It looks like an old and decayed sewer pipe.

I would advise you pack it up, (with your other Howa's,, and make the 2hr drive with them, to show the "store" in person.
There would have to be (surely) a definite manufacture issue with that one barrel in particular.

Thanks mate, I do like the Howa rifles, and have never had any trouble with the ones ive owned before this.
Just to be clear, I never fired any rounds through the barrel when in this condition in the photo.
It was uncovered during my pre-hunt checking process that I have always done, and it blew me away how dirty it was.

[Die Judicii]

And, the offered advice from the "store" is only stalling the inevitable.
Anyone with only half a brain knows that corrosion of that kind can only exist with a supply of oxygen.
So blocking the barrel only starves it of oxygen and prevents/slows it down,,,, but does nothing to address the initial problem.

DEMAND A NEW RIFLE.

[Damo300]

Id be returning that to the shop.
That does not look good at all, and to happen so quickly.

You're not using that bore cleaning solution are you?

I have only used the bore cleaner a week ago, its the Hoppes one.
This Howa was bought from the big shop in Margate, and I'm not confident they would be interested in doing anything for me.
Its also nearly 2 hour drive for me to get there.

Has anyone had contact with Howa directly?
Would that be worth trying?

Cheers
Jay

Highly unlikely the Hoppe's is the issue.
SDS reveals nothing out of the ordinary.

https://assets.unilogcorp.com/187/ITEM/DOC/HOPPES_102274354_SDS.pdf

Can see the proprietary items listed but that's their secrete sauce, and I'm pretty sure non toxic therefore identity can be protected.

What was used on the first clean?

The fact you have 2 other rifles of the same breed sitting there, which I am going to assume have been cared for the same way, with the same ingredients, one can assume it's something isolated to this rifle.

And the shop won't help you with a new rifle?
I'd be in there demanding it be sent back to howa, or find a shop that will help you.

There are plenty of options if you cannot get help, but they're gonna cost you.

HAHA i would like to demand a new replacement, but I don't expect that approach would work in that shop.
They actually advised me to plug the bore and see if the substance returns, so thats what ill do for now.
I'll do the right thing and see what happens after another week

Cheers
Jay

I'd kindly suggest back that they stick the plug in their gob and drop the rifle back to them.

Ask to speak to the big boss, go up the chain, even email howa themselves and tell them how you're being treated.
By the sounds of it, howa may have a problem here.

Otherwise,if you're prepared to take the hit, replace the barrel, or if you're in Qld, like for like swap it for another 223.

[dirtjay]

I'd kindly suggest back that they stick the plug in their gob and drop the rifle back to them.

Ask to speak to the big boss, go up the chain, even email howa themselves and tell them how you're being treated.
By the sounds of it, howa may have a problem here.

Otherwise,if you're prepared to take the hit, replace the barrel, or if you're in Qld, like for like swap it for another 223.[/quote]


Haha - Yeah it might come to that mate.
I will contact Howa about this, it'll be interesting in what they have to say.
I think if i get a helpful response from Howa, that could be good leverage at the store.

[dirtjay]

And, the offered advice from the "store" is only stalling the inevitable.
Anyone with only half a brain knows that corrosion of that kind can only exist with a supply of oxygen.
So blocking the barrel only starves it of oxygen and prevents/slows it down,,,, but does nothing to address the initial problem.

DEMAND A NEW RIFLE.

I figured as much myself, remove the oxygen - it will slow the effect.
Who plugs their rifles anyway?
Compared to the other rifles of the same brand, they are in fine condition.

[deye243]

A friend of mine in Queensland bought a Howa from that particular shop and it would not shoot for s*** did his own investigation on why did the usual things action screws bedding making sure the barrels clean and then he checked the Crown and found this

Screenshot_20261022_155947_Gallery.jpg (460.74 KiB) Viewed 189 times

the cottonbud is there there for the reflective white to show the damage he took it back to the shop and explained it doesn't group then showed them the damage obviously a factory fault they happily gave him another one bit of a mug he never checked it before he left got home set it all up in the stock putting scope on and thought maybe i better check it guess what same problem so back to the shop they quite literally yelled at him and told him to stop looking at the rifling

[Cape_Yorkee]

Put simply you HAVE TO go nuclear here with the dealer and demand a new rifle. That is extraordinary to say the least.

A friend of mine brought up a Howa 270 Win on a trip last year. He is an old hand - loves his shooting. Bashes his gear around a bit and uses it for what its intended, but at the end of the day he cleans his gear down almost better than I do. This Howa he had though was an absolute rust bucket- chamber, barrel and all. It was his favourite bush rifle so it took all the knocks and scrapes. Scary thing was it wasn't that old!!! Perhaps they've had some bad batches go through the processing line?

Either way, I'd be making some serious noise.

[Wapiti]

Someone tell me what type of carbon steel is made that basically self-destructs. There's no such thing.
There HAS to be a cause somewhere.
Some chattered rifling is just a QA stuff-up, this is something else. There is a third-party issue here, in all of these rust examples people bring up.

Plugging a barrel - I'm shaking my head from the ridiculous crap gunshop staff dribble at times. Plug a pipe with caps, trap in the oxygen mixed with humidity - there's always some in the air - then give it the rise and fall in temperatures a gunsafe has in many places people put them. Water coming out of the air.
The same thing happens in safes, because of where some people put these safes - they are moisture makers if put in a spot that has temp/humidity rise and falls too large. Close them up and they can become condensation-makers in the wrong circumstances.

Look at the big names that make safe-dehumidifiers, and the people that buy and use them because they know they have humidity issues when shutting the door on a box full of air.

[dirtjay]

Someone tell me what type of carbon steel is made that basically self-destructs. There's no such thing.
There HAS to be a cause somewhere.
Some chattered rifling is just a QA stuff-up, this is something else. There is a third-party issue here, in all of these rust examples people bring up.

Plugging a barrel - I'm shaking my head from the ridiculous crap gunshop staff dribble at times. Plug a pipe with caps, trap in the oxygen mixed with humidity - there's always some in the air - then give it the rise and fall in temperatures a gunsafe has in many places people put them. Water coming out of the air.
The same thing happens in safes, because of where some people put these safes - they are moisture makers if put in a spot that has temp/humidity rise and falls too large. Close them up and they can become condensation-makers in the wrong circumstances.

Look at the big names that make safe-dehumidifiers, and the people that buy and use them because they know they have humidity issues when shutting the door on a box full of air.

Gday Wapiti,

I totally agree, there is a cause somewhere.
What do you think it could be?
Take into consideration there are two other barrels from the same maker in the same safe, and these are unaffected.
Would you consider some type of contaminating substance, lets say with a sodium base has embedded itself and continually corroding the carbon steel?
Could that substance be practically removed in any way from the steel?

Happy to hear your thoughts

[Die Judicii]

But,,,,,,, Wapiti,,, The OP is having this problem with only ONE of his firearms. Out of how many ? And three of them are the same brand,,, and, purportedly all treated identically. It seems pretty obvious to be a problem with just the one afflicted rifle, and not his storage facility.

[Wapiti]

Yeah you're right mate, but something is wrong.

You have worked with steel so much of your life, as have I...
What steel is made that just spontaneously rusts like that ? No such thing.

The steel here is reacting to something contacting it, or some exposure conditions reacting with some product.

I really feel for the OP here, and can understand why some muppet gunshop-staff will brush him off. Saying stupid things like plugging a barrel - where do they find these clowns?
The only time this has happened to me in my whole shooting life was when I used that Boretech sh*t, and used it for storage LIKE IT SAID on the label.

And an edit: This could very well make a warranty replacement a long drawn-out mess, again I feel for the OP.
Who knows, he might get a break here.

[Die Judicii]

I agree Mate,, That it shouldn’t and normally doesn’t happen with the steel used in “normal” barrels. BUT,,, it certainly seems like this is NOT the “normal” steel in this instance. Everything thus far is screaming at being a rogue batch of steel or barrels. As for the gun shop,,,, I think to treat the rifles owner in such a way (which is obvious because he seems reticent to return) is abominable. They are just buying their own bad publicity.

[dirtjay]

I agree Mate,, That it shouldn’t and normally doesn’t happen with the steel used in “normal” barrels. BUT,,, it certainly seems like this is NOT the “normal” steel in this instance. Everything thus far is screaming at being a rogue batch of steel or barrels. As for the gun shop,,,, I think to treat the rifles owner in such a way (which is obvious because he seems reticent to return) is abominable. They are just buying their own bad publicity.

Die Judicii
You are correct in assuming my hesitancy to return the rifle.
For a couple reasons, it is a big effort for me to get there during their opening hours - although it can be done.
I purchased this rifle through them as they said they had one being imported and in transit,
As you would know this store can be difficult to deal with at various levels, I have had a bad experience there before, and i personally would expect to be told I am the problem, which is a fair assessment at seeing the condition being dealt with here. I'm not lining up in that retail store to be told I'm an idiot, lose half a day and have absolutely no help.
The only comparison for my cleaning and maintenance process I have is the condition of the other matching brand barrels, and even then they could easily say I have cleaned those prior to the problem barrel.
I have emailed Howa (OSA) in the US, to see what their thoughts are, and have not had a reply yet.

The only information i have read that i havent tried is a complete wash down in a warm water and detergent solution.
This was mentioned in an article I read, apparently to dissolve any corrosive substances in the pores of the metal and completely rinse the bore clean.
Then dry, and apply oils as you normally would for storage.
Thoughts on that process?

I do appreciate you guys commenting and sharing your opinions, there is a great understanding of metallurgy that is worth sharing.
I will wait a week, check the barrel and asses what to do next.

[Wapiti]

Yes I agree, something is definately wrong. Completely agree. And it reads like the OP is doing everything right.

Strange it's happening to one rifle. I can't see where he says that his other carbon-steel rifles have had exactly the same treatment with the same chemicals, at the same time, in the same conditions. Am I missing this?

Steel used in barrels is decided on for it's suitability for the task, metallurgists are usually involved to choose from available steel grades. it would be a BIG manufacturer who specifies an element mix from a steel manufacturer to make batches for them. In any case, that makes NO difference, there is no carbon-steel that just spontaneously corrodes no matter how much care is take.
There definately is cause and affect.

Remember the old ammo we used to get, ex-mil stuff? I remember 30-06, .303 and even 7.62 Nato stuff with mercuric primers that left salts in the bore, and cordite that did the same thing?
No matter what you did with solvents and oil, the salts embedded reacted with the steel regardless of the fact that there was a covering of oil over it stopping the oxygen from starting the change from iron to oxide. Because this contamination had it's own oxygen factory.
Remember how boiling water down from the chamber - through a small funnel - dissolved and carried all the salts out? We had to do that after every shoot.

As I said, something is causing this, and it's not the steel itself. Something - whether it was put in there before the OP brought the rifle home, or what product he's using that is causing this steel mix to react - is what's causing this.
There is no carbon steel grade that just tries to turn back to iron oxide if it's got nothing to chemically react with.

[straightshooter]

Wapiti has it somewhat right.
What could possibly be the difference between that barrel and the two other barrels?
The photo of the barrel, although not very sharp, seems to show the flowery type of rust one would get from using corrosive primers.

Once upon a time, after doing a proper solvent clean and thorough patch out, this was the the best method for dealing with corrosive primers.
What is needed is a small gas stove, a small old pot with about a liter of water, a small quantity of soluble oil such a Young's 303 oil or white machining oil added and a patch that tightly fits the barrel on a jag on the cleaning rod.
When the mixture is boiling push the cleaning rod through the barrel with about half of of the patch protruding, put the muzzle into the boiling mixture and hold it there and work the cleaning rod up and down drawing the hot water repeatedly the full length of the rifling Don't pull it beyond the chamber.
The idea is to draw the boiling water up often enough to mechanically remove and dissolve any remaining corrosive residue while leaving the barrel hot, then after a few seconds the barrel will have internally dried so then immediately push through an oiled patch.
This method ensures that oil is drawn into the tiny pores of the barrel as it cools.

Further admonitions are:
Never use two different brands of solvent at the same cleaning session unless expressly recommended by the manufacturers. We aren't industrial chemists and have no idea of potential incompatibility.
Never leave cleaning solvents in the barrel for week on end. The salts generated by the solvent acting on the copper are hygroscopic and when the carriers in the solvent have dried out the salts will attract water and cause etching or pitting if left undisturbed even in a "stainless" barrel.
Be cautious with the many hyped up new wonder cleaners that seem to target lazy stupid or is that stupid lazy people.
Marketing seems have the effect of turning people who mostly don't know which direction their a$$ is pointing into experts.

[dirtjay]

Just to clarify my cleaning products and processes.
I have used G96 cleaner for longer than i can remember, and it has not failed me with any of my current and previous firearms.
The other Howa barrels including this problem barrel are all carbon steel. The three Howas are all in the same safe.
I have a stainless barrel from Ruger, and a carbon steel from Lithgow Arms no problems with any of my other barrels.
The bore cleaner i have only ever owned and used is the Hoppes #9, and applied and used as per instructions, this has always completed the job for its purpose.
My process includes brass brushes, cotton mops and patches, and jags.
The corrosive substance has returned twice after first noticing it, with a week between 2nd and 3rd time. The next check is tomorrow, being a week since the 3rd check.
The first time was out on a trip, and part of pre-hunt check i noticed in the end of the barrel, and cleaned it out. I was concerned then, hence the regular checking now.
The substance almost looks like a furry fungus, as I cannot see the rifling as i would expect with surface rust.

I would ideally like to remove this corrosion, and not have it return.
If there are other similar symptoms people have had, how was it cured?
The hot water treatment is something i am going to try tomorrow, what have i got to lose.
I actually think the barrel will be damaged beyond purposeful use now, so it is worth figuring out.
I might have lost this rifle before 50 rounds, and i don't think its due to something I've done to it.
And i dont believe i would be lucky enough to be given a new replacement one from the place of purchase.