If you buy an airgun, scope and mounts from Airguns of Arizona, they will put the combination together for you and sight it in before it is shipped to you. Most of the time, AoA’s Kip Perow gets the job of mounting the scope and making sure that everything is as it should be, so I asked Kip to walk me through the process.
“The first thing you need to do is to determine where your eye relief is,” he said. To do that, you mount the rings loosely on the gun – firm enough to stay on but not so loose as to fall off. Put the scope on, set it on the highest power (because that’s where eye relief is most critical), and gently position it for your eye relief when you are in correct shooting position.
Perow says, “When I set a gun up for a customer who has come into the store, I have them mount the gun with their eyes closed. I tell them to relax their head and neck, then open their eyes. If they move their head forward, the scope needs to come back. If they move their head back, the scope needs to go forward.”
Once you get the eye relief properly set, tighten down the bolts that hold the scope rings to the scope rail on the rifle. At that point, it’s time to get the crosshairs aligned straight up and down.
“Don’t try to do this by pulling the gun to your shoulder,” Perow says. “Right handed shooters will tend to cant the rifle to the left, and lefthanders will tend to cant to the right. Instead, set the gun in a solid rest, make sure the gun is level, and sight on a plumb bob or the corner of a wall to get the crosshairs vertical.”
When the crosshairs are squared away, it’s time to tighten the scope in the rings. Tighten all the top strap screws until they are just barely snug, with an even gap on the left and the right side of the scope. Then tighten each screw in an X pattern, one-eighth of a turn at a time. Do four cycles of tightening on the front mount, then four cycles on the rear mount, then repeat as needed. Make sure you are maintaining an even gap from side to side as you complete your tightening cycles. “You want to get them as tight as you can on a spring gun,” Perow says.
If you find you don’t have enough vertical adjustment to get the scope sighted in, you can place a shim under the scope on the rear mount to compensate. “You can use brass sheeting from a hardware store or plastic cut out of standard water bottles,” he says.
He adds, “Most of the time, when we need to shim a scope, it will be on an RWS springer, and it might take a couple of shims. Occasionally we have to shim a scope on a precharged air rifle if the scope is one that has only one-eight inch adjustment.”
If you want to avoid the shimming issue altogether, Perow recommends the Beeman 5039 mount. “It is fully adjustable for windage and elevation and is the best adjustable mount on the market,” he says. “It’s expensive, but it maintains its setting.”
Til next time, aim true and shoot straight.
– Jock Elliott