Tulloch, if you can find a used wood stock, put that on the rifle, and seal it up, before doing the same to your pretty stock.
The A-Bolt II has a tough, polymer finish like the Remington M700. You just need to remove the barreled action and recoil pad, and seal the inside.
Do not use oil finishes, like linseed oil or tung oil, as they take on water. That, or waxes which take on water, are what cause the rings on table tops where cold drink glasses sat.
Make sure the wood is good and dry. Mask off the nice exterior finish with 3M painters tape.
You want to seal the raw wood with a sealer for polyurethane, like Varuthane ( used on sailboat brightwork), or Permalyn. You brush it on, let the wood soak it up, brush on some more while still wet. It may take several applications over a period of 20 minutes. Then hang the stock in a ventilated room and let it dry overnight. The next day, apply the polyurethane inside and to the butt.
A second method is to use a polymerized oil, which will seal and then will do the top coat, the next day, like Casey's Tru Oil or Formby's Tung Oil, which is not really Tung oil.
If you are starting from scratch, a laminated or wood stock can be finished inside and out with a thin, penetrating epoxy that they uses to make cedar strip kayaks and canoes, like Gudgeon. This is what they did with the later M-14 stocks in Vietnam, until they went to the fiberglass stocks. The M700 was coated with polyurethane inside, or the heavier M24 type stock was impregnated with epoxy, then some were painted over that. But these epoxy finishes I am talking about are clear. The only problem is they yellow in the sun, so you have to put on a top finish of something like a poly with UV additives in it.