I thought I had my rifle zeroed with a new load using partitions. It is a 308Win and I had it zeroed 2 inches high at 100 as per tradition. I did the zeroing a while back and knew what adjustments I would need so made the changes and checked it with two rounds off a bipod that went on top of each other. Yesterday I shot it at 100 and the first shot went about 3 inches high while the 2nd went almost dead on the bull. Stuff happens. Another two shots and same pattern so I had two groups forming on the target one 3 inches high and one right at the point of aim. This wasn't in the plan. checked mod was tight etc. but all OK.
I then took out my Hornady Spire Point load and it was giving me only one group on the target. So, I set the rifle back to the HSP zero and we did some plinking out to 350ish yards and all was OK.
Has anyone any suggestions as to what is going wrong with the partitions? I'm pretty sure it isn't a rifle/scope problem as the other load shot OK. I've no idea of velocity but it is a max load however it was giving me good groups in the past and after zeroing put two check shots on top of each other. Of course it could have been me and I can't eliminate that but seems odd that I was shooting the other load OK to 350 yards while the partitions wouldn't group at 100.
All thoughts and suggestions gratefully received.