In real life, to change the zero of your scoped rifle, you must turn the elevation turret a certain number of clicks. The number of clicks to turn depends on the range that you wish to zero to, the ballistics of your current cartridge, etc. Please implement this for sniper scopes, so that, for example, I can click up by 2.8 mils to adjust for range. Real scopes don't have magical zero buttons on them (well, except maybe thermal scopes), and it would be nice to be able to employ real techniques in game, both for the sake of authenticity, and as an added layer of interest and immersion.
Presumably, the scopes ought to start out zeroed to a default range, such as 300 or 600m or something (talk to a real life sniper to find out typical defaults, maybe?) so you don't have to sit there and make adjustments every time you spawn in. But for changing the zero, let us use mil or moa clicks like you would in real life.