How to Mount a Riflescope

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posted on May 14, 2019
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When mounting a scope on a rifle, you’ll need to adjust the eye relief and make sure the reticle is square to the bore before tightening the ring screws. Here’s how to do it correctly the first time.

Eye Relief
Adjust the screws in the rings to lightly hold the scope so it will slide back and forth with a little pressure. Turn the scope up to its highest magnification, and holding the empty rifle in the shooting position, move the scope back and forth until you have a full view with no black ring in the view.

Lower the rifle, then close your eyes and mount the (unloaded) rifle as if you were going to shoot. Now open your eyes and move your head forward until the black ring starts to appear in the scope. Stop and move your head back until the black ring again appears. The location of your face when you mount the rifle should be halfway between the two. Adjust the scope back or forward until it is. Check with the scope at both the highest and lowest power settings.

Reticle Alignment
The reticle must be square to the bore or the gun will not shoot well at longer range. For many years, I simply held the rifle as straight as I could while looking at a white wall through the scope and adjusted by eye. Then I learned the right way to do it. What I’ve learned is that like any project, it’s best to use tools designed for the job. You use a screwdriver or Torx wrench to tighten the screws, right? You need the correct tool to align the reticle as well.

1. Segway Reticle Leveler
The inventor of this tool came to my town and took my wife and me out to dinner many years ago. The purpose was to show me this tool and to ask for ideas on how to market it. I’ve had one on my workbench ever since and have used it to mount hundreds, perhaps thousands, of scopes.

The brass bar sits on the flat mounting base and the plastic squares go on either side of your scope. It’s all held in place with rubber bands. You look through the scope and see that the horizontal crosshair is aligned with the same location on each of the tool, which means it’s square to the base.

2. Wheeler Professional Reticle Leveling System
As a full-time gun writer and a part-time gunsmith, I mount a lot of scopes. This tool makes life a bit easier. The barrel clamp level is attached to the gun’s barrel while the smaller level is fitted on a flat surface that is square to the axis of the gun, like a scope mount base or rail.

Level the gun using the smaller level. It helps to have the gun in a gun vise or cleaning cradle. Then adjust the barrel level to match and clamp it tight. Once the scope is mounted, level the rifle with the barrel level and place the small level on the scope turret. Turn the scope in the rings until the two levels match, then tighten the screws.

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