Dear Mr. Gun,
I’ve read with some interest your tracks on soaked autoloaders. What worries does the two-holer have? It seem to me the firearm industry does a great job on finishing the outside/visible parts of wood, but really spare the gue when it comes to the inside of the forearm and other places where the wood meets the metal. My older guns show evidence of soaking through the end grain either by moisture or cleaning liquids. Lately I’ve had my gunsmith apply his witches brew to both ends of the stock when he installs recoil pads. What about the forend, etc.?
You mention soaking through at the stock due to moisture or cleaning liquids. It is probably not water as that evaporates quite quickly (though water causes other obvious problems). Normal cleaning liquids of the spray on Gun Scrubber type seldom cause that soaking that you describe. They may eat plastic parts and plastic finishes though. What you have sounds like good old gun oil. Half the oil soaking problem can be solved by trying to keep the oil out of the wood in the first place.
When I get a new O/U, I always take the stock and forend off and apply several coats of Hoppe’s (different company) tung oil or Birchwood Casey’s Tru-Oil to the inside of the forend and the end grains of the stock, paying particular attention to the head of the stock where it mates with the receiver and inside that area.
When I store my shotguns in the safe, I always store them muzzle DOWN. This keep any errant oil out of the head of the stock where it does the most damage.
When I clean my guns, I try never to get too much oil on the metal so as to prevent its running down and soaking into things. Oil is always best applied sparingly.
As you have found, if you do oil soak some wood, gunsmiths can use an absorbent powder marketed by Brownells to leech the oil out. Still, it is better to avoid soaking in the first place by applying some Tru-Oil..
Shotgun Report’s Technoid