The other day, I loaded up a few rounds for my .243 Winchester, and tried out some new powder- Winchester 760. I loaded up some 95 gr Nosler Ballistic Tips over 41 grains of 760. The Lee Reloading Manual lists a maximum charge of 42 grains, so I figured 41 would be just fine. This rifle usually shoots under MOA, but with this load, it put my first two shots very close together, then the rest shot around 2 MOA. Weird. Once I finished shooting, I grabbed my brass off the ground and noticed that one of the shells was very black and had a small hole in the case head. It was just touching the edge of the primer. Further inspection revealed a matching dent in the .243's bolt face. I checked and double-checked, and my powder charge was, indeed, set at 41 grains. All subsequent groups from this gun have been 1.5- 2 MOA, and showed erratic tendencies, or stringing. Anyone have any advice, or is my beloved .243 now a wallhanger?