With a little bit of wood, some stain, and an afternoon of fun at the range, you too can make this 100% Merica project as an xmas gift.

Obviously, you'll want to work with solid wood for a project like this. While plywood is available in pretty, very stable sheets, I don't think you'll be able to friction fit brass casings into it. There's just too much resin and glue. Same goes for really dense hardwoods. You could probably swing this through an oak, but poplar is a good choice also. It's soft enough to make this easy, yet the tight grain will add visual appeal.

Now the fun part. You're going to need a ton of empty cartridges. Sure, you can buy empty cases at a gun store like Murf's in Duncan, or even Academy... but it'd make more sense to buy some cheap bulk ammo and go harvest those materials yourself. I'd probably just leave the struck primers in too. They're not much of an eyesore.

So, in essence, you'll need a piece of wood, stain, casings, and a hammer. Get to it.