Another issue I found on my Russian Mosins is that the milsurp copper washed mild steel jackets on the bullets produces massive amounts of copper fouling in only a few rounds fired. I spent hours when the guns were near new to me cleaning and de-coppering the bores. One session with milsurp ammo shooting three paper packs of ammo and the copper fouling was back with the same amount and time needed to clean as before.
Just dip the bullets in grease. This will eliminate jacket fouling 100%. Early jacketed bullets were greased for a number of Nations. I have found, from a 1908 reference, that the early Carcano ammunition had greased bullets, the Austrian service rifle, early Russian Nagant ammunition was issued with greased bullets.
And of course, the Swiss issued service rifle ammunition up to the 1980's with a grease ring.
While most other nations abandoned greased bullets once they got rid of cupronickel jackets or plain steel jackets, because greased bullets are messy, I know the Australians were greasing their 303 bullets in the 1930’s, however the Swiss kept using greased bullets because it improved accuracy.
I have dipped bullets in lubriplate 130, GI rifle grease, vaseline, axle grease, etc. No fouling what so ever, and shoots good.