That was going to be my suggestion too - using steel wool or grit to change the glossy finish to satin.The trick is to do it nice and even so it looks nice.

I have a bunch of refinishing books at home and I'd look in therefor grit # suggestions, but ideas that come to mind off hand from past projects and stuff I have laying around are: rubbing compound (the heavier grits), 500 or finer paper, or other liquid or powder grits that are preliminary steps when you're trying to rub out a lacquer or enamel into a gloss finish. I have enough of this kind of stuff on hand that I'd try it and I'm sure that I'd come up with something that I could make a nice smooth, but duller finish. Almost any technique that would be used to polish (or in the reverse- to dull) a painted metal finish, would be the same for a lacquered or enameled wood finish. Your library willl have dozens of books on car and/or furniture finishing. There are many shops that specialize in car and furniture finishing or detailing.

Worst case if I did the job, is it would be unsatisfactory and I'd end up stripping it and using something nonglossy. I would think stripping a gun stock would be fairly easy since you can completely remove it from thegun. I can think of several penetrating, but non-glossy finishes that would probably be satisfactory depending on personal taste.

Back to grit: The steps you always go through in any polishing project whether a car or woodworking involve intermediate steps which leave a satin finish, progressively shining up to gloss.So all you have to do is work backwards, picking the stage of dullness you want to end up at. And yes very fine steel wool is a possibility as suggested. But rubbing compound and super, (super, super) fine sandpaper are other possibilities. Call or stop in any place that sells products for refinishing furniture or autos - they would knowand would probably be happy to give you some quick advice. or sell you what you need.

Sounds like fun to me! If my gun stock wasn't already a non-glossy finish, I might do it myself. Good luck.