I have 2 Brown Pound'r stocks, and they have served me well. Good lightweight stocks that have tremendous strength for their weight.
Yes, to fill the barrel channel, you would just use any epoxy you'd normally use for bedding any other rifle stock but depending on how wide the gap is you need to fill, you may add a lot of weight to the stock in the process of filling. If you want to maintain as light a weight as possible in your gap filling, use a thinner yet strong epoxy like West Systems and mix in micro-balloons (tiny glass bubbles that you can buy from many sources on the 'net). Micro-balloons comes in a powder form. The MB powder both thickens the epoxy and makes the cured epoxy lighter because of the tiny air pockets, yet doesn't reduce strength much. After mixing the epoxy, you just keep adding MB powder until you achieve the thickness you want, approximating the thickness of a normal bedding epoxy. Micro-balloons are used a lot in boat building, so you can buy it from most companies that sell boat building supplies. When using micro-balloons, you have to use a thin epoxy in order to properly suspend and distribute the tiny micro-balloon granules throughout the epoxy mix. I prefer West Systems epoxy with their "207" hardener for this application because it is extremely strong (being the epoxy most commonly used in boat building), thin enough that it works well with the micro-balloons, and gives you about 20 min of working time. Regular bedding epoxy in gel or "putty" consistency won't work very well with the micro-balloons because it is already too thick as-is to properly mix in the micro-balloons and properly suspend them throughout.
If you want to free float your barrel and maintain as small a gap as possible, wrap the barrel in tape, then coat the tape with your release agent. Once the epoxy cures, your gap will only be the thickness of the tape you used. Allow the epoxy to squeeze out along the barrel channel so you will have plenty of excess epoxy height to sand back and form a sharp line on the flats on the top of the barrel channel where the stock forend and barrel mate.
You finish a Brown Pound'r the same way you would any other synthetic stock, except if you sand too deep, the Kevlar fabric underneath the primer will really "fuzz up," as the Kevlar doesn't want to "cut" cleanly. This is just the nature of the material. It's no big deal if this happens; you can just apply epoxy over the "fuzz" with a paint brush, then sand back after the epoxy cures. Any paint that you'd normally use on any other synthetic stock works fine on the Brown Pound'r. Just make sure you fill any pores, imperfections, seams, and exposed Kevlar fabric with epoxy or Bondo and sand smooth to get an even surface before painting. It isn't necessary to prime as long as you have a smooth sanded surface; the epoxy fill is your primer. I use 220 grit paper for the sanding, with a sanding block for the flats, sandpaper wrapped around wood dowels for the rounded surfaces in areas like the comb flutes.
As for texturing the stock, I've done that in 2 ways. One method is to apply thin epoxy over the stock and right as the epoxy is starting to get really sticky just prior to it setting up, stipple the surface with a sea sponge or piece of Scotch Brite pad. This requires some experimentation on a piece of scrap material to get the technique down to your satisfaction. Brownells sells a "Spray Grit" product (
https://www.brownells.com/gunsmith-...t-filled-paints/spray-grit-prod1140.aspx ) that also works well and is much easier to use than the epoxy stipple method I described, but you still have to experiment a little with spray method/speed to get the texture you want.
My preferred paint for all synthetic stocks is Lauer Weaponry's "Duracoat" because they have a huge selection of colors and because Duracoat is a polyurethane much like the automotive polyurethane paints, which is extremely tough/impact resistant. It wears extremely well. It is also easy to apply, fast curing, and resists runs really well if your spray technique isn't the best, so it's very forgiving. They have Duracoat clear coat in 3 sheens -- gloss, satin, and matte. I always spray clear over my painted stock finishes because it evens out the color coat sheen, looks better, and provides extra wear-resistance. It's available in either bottles of paint/catalyst that you mix and use in a spray rig or airbrush or a ready to go specialized spray can that you press a button on the bottom of the can to activate the catalyst while still inside the can. The only disadvantage to Duracoat is it's pretty expensive.
