How about coloured dyes? Really going for a deep dark red like you see on some SKS's, How should I strip the original finish?
dyes are great (you can get aniline dyes from lee valley) you can mix and tint to whatever colour you want - if it's not what you like, keep applying. I use mostly mahogany red, mahogany brown and 'red for tinting' in my stocks. things to think about:
- all the original finish needs to be "gone" or you will get blotches
- dyes (mostly) are not UV safe, you will need a sealer or some kind of UV safe top coat (dyes are mostly used by luthiers - ever seen a guitar shop without a UV screen in the front window?)
- dyes come in water, alcohol and oil based. water is the most forgiving.
- dye sounds expensive when you look at the $$ tag, but 2 years later I am still working on all the dye I bough with no end in sight.... it goes a looooong way
with a dark wood like walnut, you are going to have to add a lot of pigment to see a colour change, a stain may actually be the way to go (since I am assuming that the wood probably does not have 'presentation grade' figure to it.) stain will also be easier and faster.
while shellac has wonderful properties, easy to work with levels well and looks great, it is not durable. if you want a pretty wall hanger, go for it, if you want to shoot the gun go with a polymerized finish, oils, varnish or lacquer. (the solvent for shellac is alcohol, so don't spill your beer or any sort of bore solvent on it!)
stipping the original finish? figure out what the existing finish is, then use the appropriate solvent for it.
your finishing options are vast and varied - depends on what you want the end result to look like, high gloss is work intensive, use a polymerised tung sealer followed by finish of the same, a more traditional flat look ... just a few (2/3) applications of a pure tung or linseed (tung cures faster than linseed ~slightly
you want that flat look to have a bit of sheen to it? wax.
- pure oils (tung or linseed) by themselves will never give you a gloss finish
- polymerized oils will give you the finish stated on the can/jar/whatever, semi-gloss or gloss
- tru-oil *is* a polymerized linseed oil.
- I have no experience with varnishes or lacquers , so I can't speak to that.
- shellac is absolutely beautiful to work with and behold. but not appropriate for a gun.
- if you need to seal pores, the aforementioned tru-oil sanding method will work, but you fill the pores with particles, a sealer will give you 100% better results, though if the wood has no figure, it really does not matter.
1. tru-oil is fast, easy and readily available
2. everything else is a lot more work
3. you can use ANY of the above finish/combination of finishes, waxes/sealers over a dye job.