With elevation depending on the scope one click at 100 can be 1 inch then depending on the round 6oo yards could be several feet or more. Every click / adjustment matters more so the further out you go. This is why all quality scope have turrets you can free up and set to exact zero. This is also why every person who shoots well returns his dials to zero every time they change location or range.Yep. my nikons are slightly off, but not enough to matter.. A click is still a click.