I have refinished 2 rifles because the poly finish was chipping and bubbling off.One was a Marlin 336 I sanded the finish off and ended up removing too much wood in the process.
The second was a Rem 742. I bought Brownells gunstock finish remover. I slathered it all over the wood let it work for the recommended time then washed the finish off with a garden hose and scrubbed it with a plastic scrub brush. I let the stocks dry and did it again the next day and all the finish was off. I let the wood dry for a couple of weeks then made a paste of Methanol and calcium carbonate powder and brushed it on the stocks. This removed the oil from the wood. I did this a couple of times also.and just brushed it off the wood.
This whole process took some time but the actual cost and labor was minimal. I refinished with tung oil and lots of rubbing and steel wooling.
