I have a theory but I'm not sure what's going on. I worked up a load for my 6.5 Creedmoor. At 150 yards, I put 5 rounds in the same hole. At 400 yards, the group size expands to 4-5". At 1000 yards, the group is 4.5 and 5.5 inches. I shot 400yrd and 1000yrd groups 3 different times with the same results. Any ideas?