I'm loading 240 Weatherby magnum with 50-52 grains of H4831sc and Sierra Pro hunter 100 grainers with Federal Gold Medal primers 210. My best groups are around 51 grains. I get two shots touching and one flyer about 3/4 to 7/8 inches away. Can this be due to my bullet seating depth, or can changing primers have an impact on this? Any help would be greatly appreciated.