Home All Scope Mounting Tip: Using a Bubble Level : By Scott Mayer

Scope Mounting Tip: Using a Bubble Level : By Scott Mayer

Objective close to barrel.

Scope Mounting Tip

For the most part, mounting a scope is a home-gunsmithing proposition. Most guns today come either pre-drilled and tapped for bases or with some type of rail system for tip-off rings. I end up mounting scopes a lot simply because of the nature of my work and usually the biggest challenges are either bases that are too low because the objective bell is too large or rings spaced too close or too far apart for the length scope I want to use.

Even if everything falls nicely into place, there is one area often overlooked that you should pay attention to, and that’s leveling your crosshairs.

Bullet trajectory is a bit more involved than I can get into in a blog post, but at the risk of oversimplifying things, gravity begins pulling downward on a bullet the instant it leaves the muzzle. And because a scope is mounted above the bore, you have to launch bullets at an upward angle to hit something at a distance. If your gun is canted, you end up launching a bullet either upward and to the right or left depending on which way you cant the gun. It really doesn’t make a bit of difference at close range, but stretch things and you can make a bad shot because of cant.

You can go a long way toward reducing cant by having a level reticle because your eye will automatically want to level the crosshair when you’re shooting, but if your scope isn’t level in the first place, you’re working with a built-in error.
Leveling a scope is simple.  All you need is a small bubble level. I use a line level. When you mount your scope, set your rifle in a vise and put the level on a flat spot on the gun. It can be the rail, tang, possibly the magazine floorplate or inside the triggerguard—it doesn’t matter where—so long as it’s a flat spot on the top or bottom side of the gun. Level the gun, and tighten the vise.

Next, mount the scope loosely, then set the level on the top scope turret and rotate the scope until it is level.  With the gun and scope both level, tighten the rings and your crosshairs should be level and your tendency to cant the gun reduced.



–Scott Mayer


“Shooting Guns & Having Fun”

Scott Mayer
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