What do you get when you get a new scope? I was told that you want to set it at its "mechanical zero". Which I guess is basically counting how many clicks it takes to get all the way to the top of the elevation and then counting how many clocks it takes to get all the way to the bottom and basically making sure it's right in the middle. And then doing the same thing for the windage adjustments.. Is this really necessary? Or just take it out and zero it at whatever yardage you want it zeroed at.....?