I have a M77 300win mag. synthetic stock and have had it in the woods about 3 seasons. I keep my gun in a case that has silica packs in it. What my problem is, is the stock and forearm has a white film all over it. The first time it done this, I put petroleum jelly on it. A week later, same thing. I then put armor-all on my gun and yet again the same thing; white film. Can someone tell me what this is and how I can fix this problem, or even if I can.