What is wrong with my barrel?

[bryanfields]

Hey,
I've got a 270 Xbolt that used to be an incredible shooter... shot multiple 5 shot groups in the .4s. However, the group sizes have since opened up over 1" and I've been scratching my head trying to figure out why. I did all the normal stuff, checking scope, rings, action screws, brass, even trying to re-work the load. I recently bought a bore scope so I could take a look at the barrel of this gun and my other rifles. I compared the barrel of my 270 to several other guns and found some things in this barrel that I didn't find in any other gun. I'll post pics below.
Pic 1 looks to be some kind of fouling, but I don't know. I've used multiple different types of cleaners (foams, Butch's, Boretech Cu2, etc) with both patches and bronze brush. This evening I switched to Losso and the patches are coming out black, black.
Pic 2 seems to show some kind of scarring/pitting???
Pic 3 this is toward the very end of the barrel (muzzle). I have no idea what this is.
Can anyone help me interpret these photos and advise me on steps I should take moving forward? Thank you in advance.

 

[Bob Wright]

What can you tell us about the barrel. Rounds fired, factory/aftermarket, previous care or rode hard and left dirty in a guncase in humid weather?
From what I see it's corrosion or spalling (metal areas detaching) caused by corrosion, heat, friction.
I would be interested to see what bore polish such as JB's would show. It does look pretty rough.

 

[bryanfields]

You bet. Gun is 7 years old. Probably 200-300 rounds through it. It's a factory barrel. I'm the original owner.
I've always stored it inside. I don't recall the barrel getting wet, but I hunted in southeast Oklahoma where it's usually pretty humid. I was not good at cleaning my guns regularly back then so maybe that's the issue?
Would you recommend I use a polish (Jb's, Simichrome, etc) as opposed to Losso's?

 

[Herbie]

tagging in

 

[Bob Wright]

Delete

 

[Bob Wright]

I would try it, anything you mentioned. About 50 strokes with a brush and patch wrapped around it tightly. Force your polish into the patch to soak it. Then put the elbow grease to it.
I have no idea what the crown looks like. That's important for sure. If satisfied with any improvement in finish, go shoot it again. If that doesn't change it, you could try David Tubbs final finish bullets. Look those up.
If that fails, then it might be time to rebarrel.
Don't think the pitting will completely disappear but it might tighten your groups some.

 

[bryanfields]

Copy that. Crown looks good.
Should I use Losso til the patches are clean? I've used 25 patches so far and they're still coming out super black.

 

[Bob Wright]

Copy that. Crown looks good.
Should I use Losso til the patches are clean? I've used 25 patches so far and they're still coming out super black.

That's probably iron (black color), and not dirty. Just polish, then clean the bore for another viewing. Carbon steel will never show perfectly clean patches in my experience compared to stainless.

 

[Dosh]

Copy that. Crown looks good.
Should I use Losso til the patches are clean? I've used 25 patches so far and they're still coming out super black.

With IOSSO the patches will always be black. Don't over stroke with it. Use a bore cleaner to remove the IOSSO residue followed by clean patches.

 

[bryanfields]

With IOSSO the patches will always be black. Don't over stroke with it. Use a bore cleaner to remove the IOSSO residue followed by clean patches.

Thanks!

 

[257 STW]

With IOSSO the patches will always be black. Don't over stroke with it. Use a bore cleaner to remove the IOSSO residue followed by clean patches.

 

[bryanfields]

I've cleaned the barrel as thoroughly as I can. I don't think anything is going to remove the scarring/malling. Next time I shoot it I'll post a report on how it does.

 

[WapitiBob]

Looks like you left something in the barrel and it's pitted. Nothing is gonna fix it.

 

[bryanfields]

Looks like you left something in the barrel and it's pitted. Nothing is gonna fix it.

What's the most likely thing that would have caused the pitting? Moisture?
I'd like to learn what I did wrong.