What kind of fouling is this mess?

I’ve found the Big 45 metal cleaner works amazing on really bad bores. It looks like a steel put scrubber except it’s a soft alloy, wrap a little around a bore brush and maybe 10 passes through might remove the raised deposits.
It won't do much with cupro-nickel, it's much harder than most copper alloys or lead.
 
Maybe some Swiss Waffenfett grease would do the trick, I think that's all they used with the K31's and they only saw cupro-nickle projectiles.
Rarely come across a K31 with a fouled up mess of a bore like this Dane M58 lol.
If I can't scrub it out, I'll send it to one of you guys with the electrode set up, I'm not that committed to building one lol.
Soaking it with some carb-out, see if that does anything, then I'll wrap a bit of chore boy around a brush and do some JB scrubbing, I'll try the blue with some kroil, see if that works a bit faster then the red.
I've tried it without much success. I believe its general purpose was as a lubricant, rust inhibitor, and to nullify corrosive primer issues.

The Swiss had, and still have stringent cleaning regimens.

Every nation in the world used cupro-nickel jackets for military bullets at one point. They all went away from them for the same reasons.

Cupro-nickel isn't a real issue if it's taken care of properly.
 
Don't worry too much about JB pore base making the patches black. They'll always come out that way. I've tried them on unused barrel blanks and they come out looking the same. As long as you are making progress I'd keep going.

Chris.
 
The JB Blue did some work, never tried it, was still new in the wrap.
Instructions say oil the bore, then do the JB patch over a brush 20 strokes, red says 100 strokes, so obviously a little finer and milder.
Only did one go, super messy with the oil, the patch disintegrated lol. Took a bunch of dry patches just to get it cleaned out after.
Lands are coming along now, grooves are still ugly but it's going to come clean I'm sure now.
 

Attachments

  • IMG_20251211_171512.jpg
    IMG_20251211_171512.jpg
    73 KB · Views: 15
Hate to say it, but that looks like pitting. Unpitted areas are getting shiny. I'd just shoot it and expect it will take a bit more cleaning because the pitting will pick up fouling.
Nice sharp crown?
 
Back
Top Bottom