I have used a mixture of 75% BLO and 25% Turpentine with great success on several gun stocks. IMO there is nothing else that protects a nicely grained piece of wood in a more beautiful way.
The Turpentine will make the BLO soak into the wood pores quicker. I apply the mixture to the surface and wipe off the excess after about 20 minutes. Apply another coat, rub it in with hands, wipe off excess and let the wood sit for a day or two. This allows the BLO to oxidize and gum up. (It is this oxidization and the resulting heat of reaction that sets carelessly disposed rags soaked with BLO on fire).
You never want BLO to oxidize on top of a wood surface as it makes a sticky mess. The BLO needs to cure in the wood to creates a waterproof finish without the artificial look of a top coating. A BLO finish is also more durable on field guns where a top coating is typically marred before the first day is over.
Yes, BLO is a material where mold will grow in moist conditions but so is wood itself. If the ambient moisture is so high for so long that mold grows on a gunstock, you have bigger problems already like severe corrosion on the metal parts.
Here are other options of protecting and beautifying wood surfaces.
Also a thin coat of clear Shellac looks great on pine IMO. I did the exposed rafters and T&G roof decking of my cottage that way. (Rigid foam insulation is on the outside between the pine decking and an OSB nail base for the shingles). We coated the wood before installation which was easier than fighting gravity afterwards. I'll probably do the same on my box van conversion.