I have an issue with my PA-63 having the hammer drop on every shot- so it has to be shot double action every shot. This is a recent occurance. I have several hundred rounds thorugh it and have changed only two things- I put in a 13 pound recoil spring and a slightly lighter hammer spring. I keep it clean and but suspect maybe some wear on the sear? The problem has only cropped up recently, the spring changes worked like a charm for quite a while, so I don't that that that is the issue. Any thoughts?