I have had a glass/slate combo call for about a year now. It used to make a good sound when I first bought it. Now, it screeches and sometimes doesn't even make a sound. The striker is practically smooth. I tried sanding it down but that only works for a very short time. I was wondering what i could do to fix this. I don't want to take a call in the woods that I can't depend on.

Have you sanded both the call and the striker?. The call surface needs Condistioning aswell. Sand the call only one way across the surface and run the striker across the friction groves...BT