I've set up a lot of long gun/scope combos for many guys and never had much of a problem other than a few ring height issues, and always check eye relief last before the final tightening. Until my bother in law's Savage 220 last year. Talk about the difference in people, I used low rings, always my first choice unless conditions warrant higher ones, and it fit me perfect. When he put it up, he was almost looking under the scope, I couldn't believe it. We found a really nice composite saddle type cheek piece that raised the cheek height 5/8", making it perfect for him, impossible for me to even look through it. Like you guys said, different people fit guns differently. As for the "change" issue, I noticed the last few years with my slug gun that I'm having to force my face a little further forward to get a good picture, before it was fine. I guess it's because I used to be 6'3", now I'm only 5'11" HAHAHA!!