A telescopic sight or scope on an air rifle can greatly improve accuracy and consistency by magnifying the target and allowing the shooter to simply place the crosshairs over the target to aim the rifle. Proper sight adjustment is key to achieving the highest degree of accuracy, and once properly set the rifle will remain true for many shooting seasons. Although adjusting or sighting in the scope is not inherently difficult, it does require significant preparation and patience.
Choose a day with little or no wind to visit an outdoor shooting range to adjust and sight in the air rifle's scope. If using an indoor range, wind will not be a factor.
Set up a target at a range comfortable for the shooter's skill level. For example, if you are used to firing at targets around 25 yards, choose that distance to adjust the scope. Hang the target carefully so that the grid lines on the target or edges of the paper are aligned vertically and horizontally, not at an angle.
Fire a grouping at the target's centre. When the range is safe to shoot, fire a group of three to five pellets at the target. Aim the scope's reticle or crosshairs at the very centre of the target each time, and disregard where the pellets are striking while shooting the group.
Locate the average centre of the grouping. Look for where most of the rounds seem to have struck, disregarding any single shot that differed greatly from the others.
Unload the rifle, rest it on the bench rest and aim again at the centre of the target. Set the rifle in the rest so that it will remain in place—aimed at the target's centre—without anyone holding it. An assistant may be helpful to hold the rifle steady.
Adjust the scope windage and elevation by turning the turret knobs on the scope. Use the appropriate tool such as a screwdriver or hex wrench to adjust the knobs if necessary; otherwise most knobs can be adjusted by hand. Turn the adjustment knobs—elevation for vertical and windage for horizontal—until the scope's reticle appears to move to the location of the shot grouping.
Fire a grouping at the target to verify the adjustment. Aim again at the centre of the target and fire the same number of pellets as before; each hit will be very close to centre.
Always obey all range safety rules and all safety guidelines for your air rifle.