I received a custom CDS M1 dial for a Mark IV 6.5-20x50 mm this past week and got a chance to shoot it today. It worked close but was off at 475 yards today. That is far as I could test it today but will shoot it again soon for additional testing.I was amazed that Leupold was able to give me a range from 100-1,200 plus yards on one dial! Anyway, back to my point. After checking zero at 100 yards, my rifle was spot on at 100, which the dial was made for. The next shots were at a measured 475 yard steel target. I turned the dial to what I thought was 475 and shot twice over the 10 inch plate, while holding center . After dialing back to 450, the shot hit at the top of the plate, which was 5 inches higher than I aimed. Is this difference normal? It has me doubting how accurate it will be once I stretch it to further distances. I mentioned what I thought was the 475 mark. The increments on the dial are in 50 yard segments. For 475, i turned halfway between 450 & 500. I am not trying to sound ignorant but is it that simple or do you have to error on the side and adjust closer to the higher mark when in between increment marks? Thanks in advance, John.