That's interesting. I had a Big Nikko that I could not get to range find consistently in the Summer. I had put a used DG scope "enhancer" on it and that kept slipping. I would then give it a tug to get it back into place. Just wonder if I was moving the eyepiece at the same time. I shot like S H 1 T anyway but I'll make sure not to move the enhancer/ pigs ear in the future.