Why 4 shots? Right or wrong, most of my group testing I do with 3 shots. I load 5 of each, test with 3, use 2 to zero the scope with the "winner". In some cases, if I read Cooper 1:12" 204 data that someone found to be superior, I'd load 6-7 of THAT load, then test using 4 or 5 shots. When I got home, the bore was pretty dirty...more than I would have expected. I probably put about 130 rounds through the rifle in total, using various bullet/powder combinations. Powders H4895, Varget, H322 and RL-10x.
Back to the subject line~any chance barrel temperature can throw things off that far, or a combination of that...plus a dirty bore? Obviously, there are lots of factors (including wind) that play a roll. It was a bit gusty yesterday.
