Follow up test to prove if it was virgin vs. once fired brass for 120 fps swing in muzzle velocity. Exact same load as original test in post 1 with all bullets set .070 off lands. Sig brass out of same box and not weight sorted. Alternated shots between virgin, once fired,virgin etc. for a total of 8 shots (all the virgin brass that I had). I threw out one virgin brass shot that was 40 fps off remaining group. Virgin brass average 2748 fps. Once fired brass average 2867 fps for once again a 120 fps advantage to the once fired. I realize that this only applies to my load, brass and rifle and am not making any blanket statements. These were shots 17 through 25 down the pipe. I appreciate all the comments and suggestions and a shout out to Dmagna.
