Damn near wore out a Sako 7mag trying to get it clean.
Finally realized I was contaminating it with a brass brush, and the
cleaner was eating my jag. Leaving green, which I thought was copper.
The.
The fugging thing wouldn't shoot decent.
Thought I might have ruined it.
After it got a bit dirty, it was normal again.
Same issue with a shotgun I use for Turkey hunting/shoots.
As the season of shoots went on, it shot better. More wins.
Solvent fine steel wool, I cleaned her up like new.
Wouldn't pattern near as well.
Untill it got some plastic built up.
Hasn't seen anything but an oil mop since.