Before you start stoning trigger parts, make sure that you have the knowledge of how triggers work. Without knowing how they work properly, you could make that GP100 a very dangerous gun. The spring kit from Wilson will reduce the trigger pull a great deal. If you decide that you want to try more advanced trigger work, get the AGI video on pistol trigger jobs. Then get a good stoning jig from Brownells to complete the job safely. Try the spring kit first and you may find that cures your problem.