I have very good luck putting a heavy coating of KROIL on all the metal parts and re-apply for several days (Remove stocks first!)
Then use 4 ought steel wool and a brass brush to work into the rusted areas. Don't rush it, sometimes it will take several applications to finally get down to the bottom of the rust.
Check under the side plate, if the insides are coated with rust/gunk, you can remove all the parts and dip everything in an ultrasonic cleaner.....this will pretty much remove anything that is removable without hurting the gun. Be sure to rinse the parts in the proper solution and dry/oil them before reassemling. My gunsmith has a tank for this and I was amazed at the results of the cleaning!
Good luck!
Then use 4 ought steel wool and a brass brush to work into the rusted areas. Don't rush it, sometimes it will take several applications to finally get down to the bottom of the rust.
Check under the side plate, if the insides are coated with rust/gunk, you can remove all the parts and dip everything in an ultrasonic cleaner.....this will pretty much remove anything that is removable without hurting the gun. Be sure to rinse the parts in the proper solution and dry/oil them before reassemling. My gunsmith has a tank for this and I was amazed at the results of the cleaning!
Good luck!