I have been loading for about 15 years, but I have just come back form the range frustrated at the results of my loads. The issue is a huge variance in MV. I confirmed each powder charge on a balance scale, and all are 69.5 grains H1000. I am shooting Hornady Brass, Fed 215M primers, and COAL of 3.40 for a 7 RM. Here are the results. These 7 were fired approximately 3 minutes apart. I probably should have fired 3, then let sit for 10 minutes to cool. my gut feel is either my charges have enough variance that it is impacting MV, or as the barrel heats and expands, I get increased pressure/velocity? 2867- Cold Bore 2996 3122 3152 3182 3108 3152 I was surprised to see MV above 3100 with this load. I have a 25" Brux Sendero contour barrel with a 1 inch brake. After a 15 minute cool down, the next 3 shot at: 2976 2969 2982 Which is what I was expecting. Does anyone have experience with these kinds of ES on loads? How did you resolve? I am confident the charges were all identical.