The lead pellet works decently for the barrel holes (front swivel) but does nothing for the rear swivel holes in the buttstock. I think the best solution there is to find a small walnut wood dowel, orient the grain as best as possible, glue a piece in each hole, work it down carefully to match the existing contours, and touch-up stain and finish. It won't be invisible, naturally, but it's a decent solution if you are hell bent to get rid of the swivel holes. If you can remove the butt plate or recoil pad or whatever you have on the end of the butt, you can actually cut a couple of small pieces out from under there with a plug cutter (available at many tool suppliers) and come nearer matching the color of the wood. I prefer to reinstall swivels, you would be surprised at how handy a nice braided leather style strap can be on a long day's upland hunt. I have several of them on my guns and absolutely love them.
