pre-64 stock issue
I have had a lot of experience with pre-64s ( own several dozen myself and have rebuild/repaired more than that), and I agree with most of what has been said. You are experiencing one of the most common problems that the pre-64 70s are known for. That is the main reason that Winchester went to the oval tang. It did not require as much precision in the wood to metal fit around the tang as the earlier (cloverleaf tangs) and more attention was paid to the recoil lug area. I agree with the poster who said that the recoil lug should be your fist concern. If the recoil lug is working the way it should, your tang area (Weakest point of the stock) will not have to do anything but hold the 2 ends together. I would start by beefing up the recoil lug area to ensure it is bearing the recoil, then concentrate on the "repair" for what has been done. Fixing the crack can normally be done without causing further damage. If the finish has been damaged, it too can be repaired if you know what you are doing. The fact is your stock is cracked an always will be, but the cracked area can actually be made stronger than the area around it. If you don't fix what has caused the problem, those stresses will be redirected into another area and another crack will develop. I have also seen this occur when the action screws are not torqued correctly. This causes uneven stress in the action area and cause unexpected things to happen (Bad accuracy, cracked stocks,etc,etc) Hope I've heled.. Tom