Most older guns will all have an oil finish like the above M1 stock. The type of oil used is the important part. Tung oil is best. It well fully dry and be very weather resistant. The other is Lin Seed oil. All old military arms were finished with Lin Seed oil. Not the best idea but it was still widely used. Lin Seed oil in it’s pure form will never fully dry. The problem with this is that moisture can still penetrate. Yes it can warp enough to make a difference but it takes a good amount of moisture. It still protects the stock but just not as well as Tung oil that dries completely. Oil finishes are a two edged sword. They are a great finish with a warm luster but it scratches easily. The great part about oil finishes is that they are the easiest to work with if you wanted to refinish the stock.
(2) RKW finish.
This finish is how the large companies like Remington and Browning get the high gloss shine on their stocks. Here are the big differences, an RKW finish does not soak very far into the wood unlike oil finishes. Oil finishes leave the wood susceptible to scratches while RKW finishes give an exterior armor to the wood that is harder than the hubs of Hades. This makes it very scratch and dent resistant. However, if you want to refinish one of these stocks you need the best stripping compound you can find and a few days of scraping.
So with that in mind your next step is just how many scratches are too many? That’s really a question only you can answer. Just keep in mind that there could be a good deal of work to get it to the condition you want it in.
Ok, now for synthetics. There are many different styles from hunter to thumb hole to the do every thing target stocks. Then there are a few finish choices. There is the usual factory black or O.D. green and then you have your dipped camo. That’s basically it. Synthetics get scratched but there is no good way to repair that. You simply have a scratched stock. It doesn’t compromise that integrity of the stock as long as it is a surface scratch and not a huge gouge. I say that because some poor quality aftermarket synthetic stocks are made of thin fiberglass filled with foam. If you find one of these stocks stay away from them.