Has this happened to anyone before? I was recently working up 100 yard loads for an AR 10 style rifle. I decided to use a lead sled to try to take me out of the equation. I made up 9 cartridges of each loading. I shot 5 cartridges of each loading and was unable to get any reasonable consistency other than velocity. I was confused and frustrated as two of the loadings used to give me reasonable accuracy. I then shot the 4 remaining cartridges of each loading with a front rest only. Grouping got a lot better across the board on all loadings. Any Ideas?