What is an Anti Cant Device and How Do You Use It?

Make sure you don’t miss out on a single shot because of rifle canting

When it comes to long range outdoor shooting, precision and accuracy is of the utmost importance, but there are several variables to take into account, one of the most difficult to deal with being wind. However, sometimes when you miss a shot, it may not be a question of incorrect wind assessment, rather it means your rifle is canted.

Rifle canting can affect its consistency between shots. When the rifle is tilted either side from shot to shot, this can cause it to fall out of line with the point of impact of the bullet. Specifically, canting causes the rifle to be out of level with the riflescope, and this can cause the shots to fall either left or right in the direction of the cant, and lower than your point of aim. The longer you leave your canted rifle unchecked, the more extreme will be the variation in your shots.

A simple fix for this problem is to equip your weapon with an anti-cant device. While they are especially recommended for long range precision shooting, there’s no reason your casual or competitive gear couldn’t benefit from minimizing its cant as well. The devices are small, non-obstructive, and not heavy on the wallet. Let’s look into using an anti-cant device along with your riflescope in greater detail.

Basics of Anti Cant Devices

The main feature of an anti-cant device is the “bubble level”, that is, the thin fluorescent tube containing gel liquid with a bubble that floats level when the device it is mounted to is also level with the earth’s gravity. You may have seen this apparatus also used on construction sites, where the bubble level is fitted in a horizontal ruler and placed on a flat surface to check if it is canted. You can use a pair of these horizontal bubble levels to check the cant of your riflescope before mounting it, but it is always easier to use an inbuilt anti-cant device to help you between shots.

It is very simple to use an anti-cant device. The main purpose of the bubble level is to ensure that the reticle is level with the earth’s gravity, even after making adjustments for elevation holding and windage. If you prefer to mount your weapon by placing the butt on your shoulder, then you can mount your riflescope offset from the rifle while keeping the bubble level in clear view. Test all adjustments to ensure that you are in a comfortable position and can also see the bubble level to the earth as you adjust the tracking of the reticle. A level reticle is less distracting than a crooked one; it helps the crosshairs not interfere with your eye.

Choosing an Anti-Cant Device

There are two types of anti-cant devices you can use: a scope-mounted bubble level, which fits around the diameter of the riflescope, and a rail-mounted bubble level, which is clamped to the rail of the riflescope. Both of these are quite inexpensive and do their job, with the price range often starting at $12.99.

The type of bubble level you choose depends on the type and size of the rifle you own since they each provide a different level of measurement. A scope-mounted ring type bubble level is generally recommended for larger, military-grade or ballistic rifles where continuous shots will require reticle holdover. However, they tend to indicate the level of the rifle more than the reticle; so while they are good for weapons that are mounted in a fixed spot or on the ground, they may not work as well for more compact weapons and high-speed competitive setups.

This is where a rail-mounted (or tube-mounted) bubble level works better. They are less distracting and more compact, and generally inexpensive compared to ring type levels. But keep in mind that a rail-mounted bubble level only has a single horizontal adjustment, whereas a scope-mounted level can be rotated until the bubble is centred once the scope’s vertical crosshair is aligned with a plumb line.

If you have a rifle with a crooked top surface, it is best recommended to use a rail-mounted bubble level. Ring type bubble levels may tend to rotate the scope’s body once tightened around it, which would then require you to purposely make the scope crooked.


Even though it’s not always visible on the competitive shooting circuit, an anti-cant device can be critical for long-range shooting to maintain consistency between shots, especially after accounting for elevation and windage. All our ZeroTech riflescopes are anti-cant device compatible, so you can bank on our precision and high-speed accuracy to serve you anytime, anywhere.