Here's a detailed process on how I chemically strip wood. I like to remove all the finish and most if not all of the original stain from my stock sets. This process will show you how to get them back to bare wood and ready for stain and finish of your choice.
There may be easier ways and different methods but this is how I do it.
When your done you can go from this....
BIX paint stripper.
This is a potent chemical paint stripper and will remove paint and grease. and Read the directions on the can. Use good rubber gloves and a wear a long sleeve shirt. This stuff burns skin but is easily diluted with water if you splash some on you accidentally. Use safety glasses. Try to use it outdoors in a well ventilated area. Dispose the used stripper in a safe place and try not to breath the fumes too long, you will get dizzy if you do. A respirator is a good thing.
Rubber gloves, various nylon brushes & scotch-brite pads & disposable aluminum roasting pans. There are lots of pan sizes. Just make sure they are deep enough.
Gather up your stock sets and remove all the metal from them. Remove the butt plate and remember to pull out the big spring from inside the rear stock under the butt plate and all the sling mounts and screws.
Put the parts in the pan. I don't pre-clean much other than wipe off the really heavy grease. BIX will dissolve most everything. Pour the stripper direct from the can. Pour slowly. Don't brush it on. It works better if you just coat the pieces uniformly.
Once you have all the pieces coated.
Cover the pan with some tin foil (it helps to stop evaporation and fumes). Let the coated pieces soak for about an hour.
After about 1/2 hour check the pieces. I will sometimes re-coat the parts with the run off at the bottom of the pan with a old brush. Don't paint them just pick up the run off and spread it on the pieces.
Just before the hour is up I use a nylon brush to break up the stripper a little.
Now the really messy part of the process starts.
Use old newspapers and wipe down the parts to get a lot of the stripper off the pieces. Then put them in a clean pan and using running water start scrubbing with the nylon brushes and scotch-brite to remove the stripper. BIX turns milky colored when in contact with water. So you will see if any stripper remains. Use lots of water. Keep using the brushes and get all the stripper off. I don't use scrapers. They have a tendency to gouge and scratch the wood.
After all the BIX is off rinse the parts with clean running water. When your done the pieces should look like this.
Rinse the wash pan out and mix a 1 part bleach 2 parts water solution. Put the pieces in the pan and weight them down. I'm using some brick veneer to hold the pieces under the solution.
I leave the pieces in the bleach solution for 2 to 3 hrs. After the time is up rinse the pieces real good again with clean running water and then blot them dry with clean rags or paper towels. Let the pieces air dry for a couple of days and they should be ready to sand, stain and finish.
(As you can see the Romanian butt stock still has a shadow of the black band showing....at this point you can either re-strip using BIX or just sand it off.)
These parts had only had 12 hrs to dry. They will lighten even more after a few days drying time and the yellow cast will disappear.
I hope I explained the stripping process clearly enough....