As for removing rust when this thread started, I would use 0000 steel wool on a caliber undersize Jag with white bore paste on it & do it over & over til rust was gone. then again with thick patches & bore paste. (It is ISSO or something like that)
I clean my rifles upside down in a cradle, use a flushing jig & the lock removed. 1/2 gal water with 1-2 oz of non-aerosol Ballistol in it & flush til it is clean. Take a breech scraper & check to see I got it all.
Clean the lock under a faucet with a toothbrush, Blow dry with air. Spray/soak with Barricade.
Dry it with patches & then squirt Non-Aerosol Barricade in the bore & pump that thoroughly & make sure it squirts out the vent hole.
Put a wet patch on the cleaning rod with jag & stand the rifle in the corner for 3 days muzzle down. Swab it one last time & then take out the rod & put it away.
I like doing them upside down as I don't want water under the lock or barrel channel.
Been doing this for prob 30 yrs now & no bore rust & have owned dozens of ML's. That waiting
3 days is Crucial. If I walk by it 1-2 day I swab it & put it back.
Takes me about 30 min to clean a rifle good. Takes ? 15 min to get set up.
I have it written down in more detail for my kids & grandkids. When I build a rifle for someone I
give them a copy of it. Some say it is too detailed. Could be, but it works. I know it is allot easier to Prevent rust, than it is to rid of rust. Your mileage may vary.

