Took my 10 year old son out shooting today to get ready for his upcoming cow elk hunt. We made sure he got the 6.5 Sherman zeroed at 100 yards and then set up on the target I had set up. I thought I had set it up at 600 yards but it ended up at 640 yards which is fine. My kid got set up and shot one round. I saw that it was low by a bit so I told him to let the barrel cool between shots but shoot two more. He did so and produced a nice 3” group so I knew it wasn’t him. I got to looking at my ballistic app to see what was wrong and somehow the app had that I zeroed 1.5” high at 100 yards which gave me lower elevation readings. I can’t figure out how it happened because I always zero dead on at 100 yards. The only thing that I can think of is that something happened on one of the updates. But we got it figured out. We had two rounds left and I decided to challenge him to a 1 rd shot each and whoever gets closer to the 3” bullseye wins. Below is the results. He shot 1.5” away from the center and I was 2.4” away. He was pretty excited and I was pretty excited for him. Deep down inside the competitive side of me wanted to wrestle him to the ground haha.