I'd say you can't do much better with plain old Break-Free CLP and regular lubrication and cleanings with only that.
Removing copper fouling from a rifle bore is another matter. Since you didn't ask about it, I'll refrain from offering an opinion.
Regards,
L
Acetone is an excellent solvent too, but make sure and oil all surfaces well after cleaning, then wipe off and lightly oil about 48 hrs later.
As long as you are careful not to bang around in the bore with your cleaning rod, the answer is no. You won't harm your gun with the solvents.
Later on in life I would experience similar problems with my .50AE Desert Eagle and solved them in a like manner. For less egregious problems than baked on copper and carbon, I've always found an dip in diesel coupled with a thorough drying and a light film of Hoppes (oil, not solvent) best for cleaning and general, between use storage. I've found various cleaning and lubricating practices work better for various methods/ lengths of storage and/ or climates.
There is no such thing as "benign" neglect.
Clean your firearms immediately after use.
The crud that collects attracts moisture (humidity) leading to the formation of acids. Over time, if "neglected", these will eat away at the bore causing severe pitting. This may be of less concern with shotguns than rifles or handguns, but it is good practice nonetheless for ALL firearms. Keep them well maintained at all times, and safely stored when not in use.
Solvents should be legalized. Anyone who disagrees with me is a jack booted thug. There is no proven physical harm associated with inhaling solvents. The War on Solvents is an abysmal failure and should be assigned to the scapheap of failed ideologies. What occurs between a consenting adult and his solvent of choice is his own business. If you disagree with me, I will spit on you!!!
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Maintenance Cleaning
If you follow these directions, you will never have to worry about ammunition being corrosive or non-corrosive. It seems that the forums are bombarded with questions about ammo being corrosive or non-corrosive. I think this because many people think you have to go to elaborate extremes to clean their rifles after using corrosive ammo. This is because many folks advocate the use of ammonia mixed with boiling water and the pouring of this water down bores. Other folks advocate long sessions of scrubbing their bores following the ammonia and hot water ritual.
I have seen very exotic recipes for cleaning after corrosive ammo that including mixing concoctions or the use the of electrolytic devices. Friends, let's keep this simple. We can start by understanding what corrosive ammo is and what that means for clean up after the range.
Corrosive ammo is corrosive because of the presence of corrosive salts in the primers used and/or the powder. When the cartridge is fired these salts are deposited in the bore and around the bolt face. Left untreated, these salts will interact with moisture in the air and corrode the metal surfaces they are on. The goal after firing this ammo is to neutralize the salts and remove the powder residue and metal fouling. To do this you will need Three products Windex with Ammonia-D Gun Scrubber and Sweet's 7.62. You will not need to boil up hot water or concoct exotic recipes. You don't even need to remove the rifle from the stock if you are careful.
Pointing the muzzle down towards the floor over an old pan, squirt a liberal amount of Windex into the chamber and bore while slowly turning the rifle. Allow it to drip out of the muzzle.
Place the rifle back on your bench ( or kitchen table ) and run a Windex soaked patch through for about 20 strokes that has been wrapped around an old bore brush. Note that this replaces the necessity of using a bore brush before cleaning with solvents.
Spray some Gun Scrubber down the bore from the chamber. Using a chamber brush, clean the chamber thoroughly. Dry patch and run a patch through for about 40 strokes liberally soaked with Sweet's 7.62. Dry patch and inspect the bore. If it still appears dirty repeat the process.
When you are satisfied that the bore is clean enough, run a final patch through to lightly coat the bore with gun oil. Clean your bolt parts by liberally spraying with the Windex and wipe dry. Then spray the inside of the with Gun Scrubber
Using a cloth, dab a little Sweet's 7.62 on the bolt face and wipe aggressively. Use a wooden matchstick or round toothpick to get into the groove surrounding the bolt face and up under the extractor. Spray with Gun Scrubber. Use a Q-tip to clean the inside of the bolt face.
Wipe the bolt parts down with a light coat of gun oil and reassemble and you are done!
Occasionally you might want to remove the barreled receiver from the stock to clean the magazine assembly.
If you stick to this cleaning process you never have to worry about what kind of ammo you use. It's quick and easy and does an excellent job. Using the boiling water method seems to leave a great deal of moisture in and around the receiver that invites corrosion a few days later.