If I were going to eliminate things that were not aiding accuracy, I'd start with the bullet. Coated bullets are all the rage, but not if you are looking for exceptional accuracy at 50 yards. Old PPC shooters used to get exceptional accuracy with lead bullets and newer "Precision" revolver shooters are causing a resurgence in interest. You really need to pick the minds of ones who know, if you can find them. You might start with joining Bullseye-L Forum