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Test Your AR 15’s Mechanical Offset

Test Your AR 15’s Mechanical Offset

June 10, 2018

The last few times you’ve been to the range have you noticed that you’re hitting high or low of your target, even though your sights are dead center? You may be dealing with a mechanical offset with your firearm. This simply means that your sights and your barrel are not aligned properly. Your line-of-sight through the optic is slightly higher than if you were to look directly down the barrel at your target. This means that you could have anywhere between a one to three inch offset. The goal of testing a mechanical offset is adjust how you shoot to increase accuracy.

In this post, we’ll briefly discuss why testing mechanical offset is important, how you can test for offset, and which type of rifle setups will require testing to ensure accuracy while firing. With accuracy in mind, Rail Scales offers hand stops, vertical grips, and forends to increase control and improve precision. You can shop online now! Otherwise, continue reading to learn more.

Why is testing mechanical offset important?

Imagine you're on the range, out hunting, or defending your home. How much difference does three inches make to achieving your intent when using your rifle? It could mean a lot. A mechanical offset with your AR 15 and sights doesn’t mean your rifle is broken, but it does mean you need to address the issue; it involves packing up your rifle, optics, and a handful of rounds and heading to the range–are you really that upset about getting to shoot more?

How to test for mechanical offset

The first step is taking a physical measurement between your optics and your barrel. This is the offset you’ll be dealing with when firing down range. As mentioned above, the offset of your rifle does not mean it’s broken; it simply means you need to train more to adjust your own firing habits to fit your setup.

Once you have the optics to barrel measurement, you’ll want to head to the range with no less than 50 rounds of ammunition. You’re going to be firing your rifle from 3, 7, 10, 15, and 25 yards to test your offset. Shoot three-round sets at each distance, checking to see if the offset is true to your measurement between optics and barrel. As you shoot at a farther distance, the bullet strike should begin to near center.

Finally, put out a new target. You’re going to shoot at the same distances as mentioned above. This time, however, you will be aiming high of center to accommodate the offset. This means that instead of holding center, you’re going to hold your optics the offset measurement above center. Once you finish shooting while holding high at the five distances, you’ll then be able to tell where you need to aim at certain distances.

Which AR 15 setups require mechanical offset testing?

Typically, any AR 15 rifle that utilizes optics other than the iron sights will need to be tested. Sights, optics, or scopes all raise line-of-sight above the barrel, which creates an offset. If you use various sights with your setup, you’ll want to test the offset for each one to make sure your accuracy is consistent.

Want to improve accuracy? Order a hand stop from Rail Scales!

A mechanical offset is relatively easy to adjust. However, once you adjust your line-of-sight to consistently hit your target, you can do more to improve accuracy and increase control. Rail Scales offers various control foregrips like hand stops, forends, and vertical grips online. You can shop for hand stops online now, or you can read our blog to learn more!