We've all seen it. The Old Shotgun, perhaps standing in the corner of an attic. Maybe behind the seat of an ancient pickup truck, usually owned by an ancient farmer. Even, sometimes, laying on the shelf of a closet, long forgotten by some family member. In our case, this one was found shoved muzzle down in a plastic barrel beside a dozen of it's brethren. Alongside other cheap single shot and bolt action shotguns, and ignored in todays high-speed/low-drag world of automatic and pump action scatter guns. Once taking a place of honor on many a young mans wall several generations ago, these are now considered just too plain by most folks.
This article is about one way of cleaning up a rusty old firearm. It's not some fancy chemical stripper, or electrolytic action. No, it's just simple elbow grease and old fashioned know how, which seems fitting for an elderly break action shotgun like this. (Please note:Try this at your own risk. It's possible to damage a firearm's finish by doing this improperly, so you are on your own!)
The trick to removing surface rust is to leave the original finish behind, or at least as much as still remains. Nothing short of rearranging the surface metal will remove pitting, but light surface rust can be removed gently while allowing the bluing to stay where it should be.
First, the firearm needs to be stripped down as far as you are comfortable doing. At the very least it needs to have the wood separated from the metal. The metal parts are going to be carefully scrubbed with very fine steel wool, and little bits tend to get into any mechanisms left assembled.
Use 4-O (0000) steel wool soaked with gun oil or lubricant, such as break-Free CLP or Ballistol. Also used, with excellent results, is plain old fashioned automatic transmission fluid. The steel wool does not need to be dripping, just wet enough to leave a heavy film as you work. Make certain that only '0000' steel wool is used. Nothing rougher, and not Scotch Brite pads. Anything rougher than 4-0 will strip and scratch the finish, and even 4-0 will do it if used harshly or dry.
Working on one section at a time, say one side of an action, scrub gently but firmly while keeping a close eye on the work. Don't let it get dry, and watch for edge wear on the bluing. Do not apply excessive force, but let the steel wool do the work. As the steel wool is used it will get 'dull', so rotate the pad often, and don't hesitate to grab a fresh pad. It's not uncommon to use an entire six pack cleaning one rifle or shotgun.
As each section smooths and the rust lifts, wipe it with clean paper towels. Re-lube the steel wool and keep working that section till it's done. Don't be stingy with the towels either, and plan on using most of a roll. Do all the exposed metal a section at a time, till all possible rust and crud is removed. Once done the scrubbing, begin detail cleaning the metalwork. Use paper towels, Q-tips, and a cleaning rod with patches. A toothbrush would not be out of line as well. Dig into the nooks and crannies, searching out the rust and debris collected over generations.
Once the outer metalwork is fully cleaned, scrub and swab the bore as well, as during any normal cleaning.
Since the subject of such a cleaning project is not likely to be a fine firearm, but probably an old workhorse, It's common to do something with the wood as well. Even if it's just a rub down with the same 4-0 steel wool dipped in linseed oil, followed by buffing. Reassemble the shotgun (or rifle) and check for function with action testing dummies or snap caps. Make sure the bore is clear and clean, and no bits of steel wool remain.
This is not something done every day, but can be a real enhancement to an old work gun that comes into your possession. One should hesitate long and hard before going after anything really old, or really valuable this way, but for a cheap shotgun or old .22 rifle, the difference can be astounding.