Some folks use a torch to carefully burn off the raised portion of the grain, but that must be done with extreme care should you choose to try it. I have never done so myself, and it seems risky to me. I'm no gambler, so I stick with what I know to work.
One well-known - but not often well-done - use of flame is to scorch a wood stock in a "tiger-stripe" pattern, in order to add interest and color to an otherwise featureless stock made of a plain wood such as birch. This method can be done well, but it can also quickly ruin a good stock. Too much fire chars the stock excessively, leaving soft charred wood which makes it even tougher to sand the wood evenly. It also tends to burn softer portions of the grain moreso than the harder parts, which can easily result in an uneven stock.
Finer all the Time
Sand the stock with progressively finer grades of sandpaper, taking care at each step to ensure that you remove the scratches caused by the previous, rougher, paper. Take your time, and don't forget to use a sanding block - the longer the block you can use on a given portion of the stock, the better.
Choose a Finish
When you're ready to apply the finish, you have a choice to make: what finish will you use? Many suitable finishes will work. Some folks use polyurethane, which makes for a tough finish but it's not for me. It looks great on my pine walls and ceiling, but I'm not fond of it on guns. I've heard from another fellow who used a polyethylene floor finish on his gun stock, saying it gave him a nice satin finish that was very tough. To each his own.
Me, I use and recommend Birchwood-Casey Tru Oil gun stock finish. Tru Oil lasts very well and is an excellent sealer. I've used it on a good number of stocks and I've never been disappointed in the results. Choose the aerosol spray or hand-rub kind, both of them work well. The spray lets you get more uniform coats on quicker, but of course you need to watch out for runs, as with any spray finish. You will get less mileage out of an aerosol can; I can finish several stocks using a single non-aerosol bottle of Tru-Oil.
One small bottle of Tru-Oil - the kind that's meant to be hand-rubbed - will finish many stocks, and in some cases gives a better finish than spraying it on. This is especially true for the first coat or two - hand-rubbing helps fill and seal the grain better than spraying does. And somehow I just enjoy applying it by hand more than spraying it on.
Applying the Finish
You want to keep your coats fairly thin - apply too much and it will run when you hang it (or stand it up) to dry. You will get a feel for it once you give it a try. Use a clean toothbrush to work it into checkering, being careful to keep it from gathering too thickly in the grooves. You don't want to fill your nice checkering with finish.
Let each coat dry thoroughly - finishing a stock is not a speedy process. Between coats, follow the directions on the package, using steel wool on the previous coat and then being careful to remove all the resulting dust before you apply the next coat. This is also a good opportunity to use the steel wool to carefully even out any flaws, such as runs, that may have been formed by the previous coat(s).
I will usually apply a minimum of four coats to the exposed surfaces of the stock, most often as many as six or eight. Keep going until the finish suits you, paying attention to the grain and making sure your finish fills and seals it properly. During the process, I usually apply a coat or two to surfaces that won't be exposed, to seal the wood against moisture - and against oil intrusion, which over time can soften and ruin a wood stock.
When you're done you will have a stock to be proud of, and one that's effectively sealed against the weather to boot.
- Russ Chastain