stock filler
yippert: It is my opinion and it was recently reinforced from (of all things) the TV programme that deals with antiques (Roadshow) that the very worst thing you can do to a stock or fine furniture is use boiled linseed oil as a finish.
I recommend you start with a urethane based spar varnish thinned with mineral spririts. Once you have applied enough coats so you have a completly glazed finish you then sand it off using diluted spar varnish. At least a 4O % dilution. When you are done sanding let the sanding sludge remain on the stock until it is very hard and dry. It will not look good at this point.
Then you wet sand it down to the wood surface with a 320 or 400 grit wet or dry sandpaper with a lubricant consisting of linseed oil and mineral spirits. Wipe the lubricant off and set the stock aside for a few days. You should now have a stock that has the pores properly filled from the initial application of diluted spar varnish.
Over this you apply multiple, very thin coats of Tru-oil , Linspeed or Pro Custom stock finish. These are modified forms of tung oil or linseed which are meant to dry hard. Emphasis on DRY. Between each coat rub the previous coat down with a lubricated green Scotch bright pad. You wipe the residiual lubricating medium off between coats. You can do the final rubdown using a felt pad and rottenstone with a boiled linseed (diluted) lubricant or go to a white Scotch Bright pad with the same lubricant. When you are done you should see darn few if any open pores in the wood. And, you will have a dead smooth surface with no dust blemishes. When you throw the stock to shoulder you will feel the smoothness of the finish: it will be slippery under your cheek.
The only thing that beats it for a sealed finish is an epoxy treatment on a warmed stock and that's a whole different story.
You will note that boiled linseed is used in this process but it is not left on the stock. It is thoroughly wiped off between stages.
Boiled linseed oil or raw tung oil are not good finishes in themselves no matter what you may have been told. Both oils are hygroscopic, meaning they will absorb water. Not good for stock stability.
Figure close to thirty days to do it right.