Zeroing in a Telescopic Scope to a Rifle.
Adjusting sights so they are properly aligned with the point of impact is called “zeroing-in” or “sighting-in”. The gun will be accurate at the distance at which it was sighted-in to. Accuracy is dependent upon the quality of the gun. If you follow the procedure below you will be able to sight your gun in based on it’s performance.
A perfectly sighted-in air gun should be able to shoot a group of shots at a paper target and make one hole. However remember your heartbeat or a slight puff of wind can affect the flight path of the pellet, so good technique has to be mastered. At a distance of 30 yards, an acceptable group could be covered by a 2p coin and a good group could be covered by a 1p coin.
Place a https://www.wighillparkguns.co.uk/product-catalogue/red-white-blue-targets/ 10 meters away from the firing line, and fire a group of pellets. (Make sure you have a good back stop and be safe.) Next, find the centre of the group, and adjust the sights accordingly. When the sight is moved to the left, the point of impact will move to the left. When the sight is moved down, the point of impact will move down, and so forth. Once the group is reasonably centred on the target, place a new paper target at the distance you actually want to sight-in your air gun and repeat the procedure. The degree of accuracy with which a sight is calibrated is almost always related to the cost of the sight.
https://www.wighillparkguns.co.uk/telescopic-scope-functionality/