How much difference in MV can a couple feet difference in distance from muzzle to Chrono make ? Shot my 155's a week earlier and was getting averages 2950 +, was first time used chrono and didn't measure or take note of the distance, althouogh I know it was right in the area of 10 feet or maybe closer, but not as close as 5. Shot again just Tuesday and shot the same load, nothing changed , (seating depth, charge, etc.) this time though I measured out exactly 10 feet from muzzle, and never reached 2950 once, averaged right in the area of 29teens - 2920's. I know day conditions can have an effect but it was also essentially same temperature and conditions between the two days. Could I lose on average 40-50 fps with just a few feet difference in distance to chrono ?