I am a wooden boat guy and a gun owner. I do more wood refinishing on one boat than most people would do working with rifle stocks in a lifetime.
Different finishes require different removal products. Epoxy, varnish, clear coat, who knows what you have. Call the mfr and find out!
Then get the right product for the job. Lots of environmentally safe stuff out there now. If you have a poly, acetone would be the best. COAT the entire wood surface at one time. If you try to do it peacemeal you can wind up with spots on your final finish.
I no longer use a sealer, clear coat, etc on my wood. Guns or otherwise. I use baby oil. And then anytime you clean your gun, reoil the stock. Shows no scratches but if you do want to remove a scratch, sand it out lightly and reoil.
AND if you ever want to refinish, you wont have to go through the removal process again! If you know the finish on an M1 then you can visualize what you will have when you are done. If you want shiny, you may even be temped to use one of the water based products which are in use by firearm mfrs today. It is not a durable finish but it is awful to remove. I love my natural looking oil finishes.
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