A bit of surface rust should come off when cleaned. I clean my guns over a 4-8 day period. Some pitting is not uncommon on guns that are actually used every year.
Day one. Break down the gun, take apart the bolt, remove stock. Coat the entire gun with a generous amount of oil. Scrub the bore, chamber and bolt using solvent. Wipe clean. There will be a lot of carbon/rust/residue being removed at this point. Coat entire gun with oil. Wrap in old t-shirt for one day.
Day two. Repeat scrub down and coat again with a large amount of oil. There will be less reside and rust coming of the gun on day two. Wrap in t-shirt for another day.
Day three. Take time cleaning every little crevice. Q-tips work well. At this point there should not be much if any carbon/rust showing up. Just oil. Spend at least an hours getting the gun as dry as possible. Then apply a very light coating of oil.
One week later. Repeat cleaning that you did in day three. The gun should be ready to store now. You may be surprised to see some carbon/rust after the first week of storage. This is normal.
About every 2-3 months I pull out all of my guns, wipe them down, apply a light coat of oil and store again.
I treasure my guns. Couldn’t imagine loaning them to anyone. Aside from being lost, stolen or damaged, I couldn’t live with myself if someone got hurt using them.
J.