I have been banging my face against a wall with this gun since I bought it. I have tried using 3 different powders and all show pressure signs and run really slow. Tried 52 grains of 4831sc and only hit 2750fps, 57 gr of retumbo hit 2850fps, and 57 gr of RE26 hit 3000. I am thinking I have a bad barrel or chamber. Anyone have any problems like this?