Mounting a Scope

Monday, March 16, 2009

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.

Kip Perow checks a customer for scope eye relief.

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.”

Perow levels the crosshairs on a scope he is mounting.

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.

Perow uses a X-pattern to tighten the top strap screws.

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 Sportsmatch AOP55 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


  1. Jerry says:

    And if the air rifle comes with a scope and rings,the smart thing to do is send them back and tell them what crap they are.
    I ruined a BSA scope because I used the mounts that they sent with the rifle. I know how to mount scopes and the mounts were as bad or worse than the scope that came with the rifle.
    The scope would not hold still,a constant creep to the barrel of the gun. Chewing into the underside of the scope. I tried some double sided tape and still no good.
    I hope you people read this. It will save you some money and grief. .
    After a new scope and new rings. My groups all came together and the scope stayed where it was suppose to.
    They make a great air rifle,on my second set of groupings I put 6 shots in less than a dime a 10 yards.With my second new scope and new rings.
    Live and learn. Jerry

    1. Jock Elliott says:


      If the scope and rings you receive are actually defective, you are due a replacement, but if you simply think the scope and rings are crap because you don’t like the quality, then the best you can expect the manufacturer to do is to replace the ones you have with the same quality scope and rings.

      Like you, I do wish that manufacturers in general would include better scopes and rings in their package deals. Unfortunately, they are trying to compete with other manufacturers and maximize profits.

  2. Alfredo Morales says:

    The same thing happened with my $500 dollars Gamo Hunter Extreme .177. Even worse, you could never tell when the adjustable two stage trigger will actually fire…..I returned the whole miserably discouraged for a full refund the day after. Unless they do a substantial and convincing fix in a hurry on both counts, the name GAMO will never cross my mind again.

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