How to Zero the Backup Iron Sights on AR-15

While it is true that many shooters choose to put an optic of some kind on their AR-15 rifles as a primary sight, it is always a good idea to have back up iron sights. And although the two may be similar in a number of ways, these back up iron sights that are put on AR-15s are somewhat different from those that are found on other types of rifles. It is important that you know how to zero the backup iron sights on your AR-15 before you go hunting.

You will find that a vast majority of the “flat top” style AR-15 files that you can buy are fully compatible with a backup iron sight or BUIS, just in case something goes wrong with the optics on the rifle. And even though they are available in many different configurations, using them is pretty much always the same and fairly simple.

The first thing you will need to do is to make certain that your backup iron sights are installed properly and securely mounted to the rifle. If you are able to wiggle the sights around with your hand at all, they are not fully secured.

The next thing you will want to do is to mechanically zero your backup iron sights. For the rear sight, you will need to make certain that the aperture is centered in the housing.

To accomplish this, you will have to simply adjust the aperture until it goes all the way to one side. You will then want to count how many clicks are required to adjust the aperture until it goes to the other end all the way. Dive the number of clicks you count by two and adjust the aperture back by that number.

If you have a standard front sight, as most hunters with this type of rifle and sight do, you will need to adjust the base of the front sight post until it becomes level with the sight housing so you can mechanically zero it.

To accomplish this, you will have to depress the detent, which is located on the front side of the post, and turn the post simultaneously. You will be able to use the tip of a bullet or nail to do this. A multi-tool can be extremely handy when you are trying to do this, but any small, thin, pointed object will work.

After you have mechanically zeroed the backup iron sights on your rifle, you can start shooting with it. It is highly recommended that you start out by shooting at 25 yards and slowly move to longer ranges after adjusting the sights.

By doing this you will be able to save quite a bit of time and ammunition as well as headaches. The type of target you shoot at doesn’t really matter that much; almost any of them will work just fine.

It is crucial that you shoot your rifle using a position that offers lots of stability and support when zeroing your backup iron sights. You will want to avoid supporting the rifle using your muscles, and focus on using a stationary object of some kind that will not move at all.

If you are firing from a steady shooting position, you will want to fire three shots at the center of the target you are aiming for at whatever range you are shooting at. After you are finished firing the first group, make sure to check the target, measuring from the center of the group to the exact point you are aiming at. After you have done this, you can adjust your sights as needed.

For a majority of backup iron sights, you will have to adjust the front sight to move the impact of the bullet either up or down, and adjust the rear sight to alter the bullet impact to the left or right.

It is important that you take all of this information into consideration when adjust the backup iron sights on your AR-15 rifle so you can get the best possible accuracy when going hunting. Without proper accuracy, you are just wasting your time standing around in the woods.