How to Bore Sight an AR-15 (Explained in Plain English)

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When you test a new firearm, one of the most important first steps is zeroing a rifle. I’ve found an AR15 bore sighting to be invaluable for this.

Bore sighters are tools that can improve your accuracy on the first shot. They’re basically a way to zero your rifle’s sights without firing a shot. I’ve saved so much on cold shots and wasted ammo.

Since I have to zero my firearms no matter if it’s a scope or iron sight it’s always nice to have a better method. My laser also lets me zero faster and it’s versatile for almost everything in my collection.

Here’s how to bore sight an AR-15:

  1. Place a target at 25 yards.
  2. Take out the bolt. You might be able to just slide it back.
  3. Put in the laser bore sighted cartridge.
  4. Slowly replace or slide the bolt forward until it closes or touches the sight.
  5. The laser should activate.
  6. Put the laser on the center of your target.
  7. Adjust your rifle scope to line up with your laser.
  8. Remove the laser.

If you prefer the detailed steps or want to know more about bore sights, keep on reading!

What’s a Laser Bore Sight?

Lasers are the one you’ll see most often. They’re easy for beginner or veteran shooters to use. They’re also fast and relatively inexpensive.

The idea of this is to point a laser from your rifle’s chamber onto the target. It’s to help you see where the first round would land and save you money on zeroing.

They can come in red dot or green dot lasers. If you’re boresighting outdoors, I’d recommend the green laser. It stands out better and usually has more intensity. The only drawback there is that green laser bore sighters cost more than the red ones.

SiteLite Ultra Mag Green Laser Professional Boresighter
  • Guaranteed superior accuracy with a lifetime warranty
  • Fits all calibers from .22 to .50 cal. plus 20 & 12 ga. Shotguns
  • Includes the SiteLite BTS program to printout a laser boresighting target for you specific rifle and ammo

Laser intensity is also important for ranged boresighting. Red lasers can be effective at about 50 yards, generally, while I’ve been able to laze targets at 100 yards with the green.

It’s all about the color, manufacturer, and how much you want to spend on your laser bore sighter. My personal favorite is the SiteLite Ultra Mag.

I have no trouble seeing the laser on 100-yard targets and it works on almost any ranged weapon. It also lets me level my crosshairs and the battery lasts around 15 hours.

Steps to AR-15 Boresighting

Bore sighting an AR-15 is surprisingly easy. The laser dot is the most common, so I’ll focus on that as the main method. If you follow these steps, you should be able to count on your first shot being just as accurate as your last one.

Charge it

The first thing to do is to make sure your bore sighting is charged. Most come with a USB port, so it doesn’t take long and a quality laser can last for hours of use.

Place Your Target

Once it’s charged, you’ll need to set up a target. The distance is up to you, because the point is to know where your bullets are going. I like to use an indoor range to minimize factors.

If you plan to shoot at longer distances, you might be tempted to set your target at 100 yards. However, not all bore sights have a strong-enough laser to go that far.

For the best outcome, or if I’m boresighting my Glock, I like to set my target at 20 or 25 yards out. That way, I can see it easily and I know where the laser is lined up using a solid rest.

Insert the Bore Sight

Slide back the bolt on your AR-15. With other rifles, you might have to take out the upper receiver to fit your laser. I haven’t had that problem with the AR-15, though larger rifle’s bore sights might mean removing the bolt completely first.

With the chamber clear, put in your laser bore sighter. It should go in the same way you’d slide in a round. Once it’s in, close the bolt and lock it down.

On a side note, don’t force it. If the bolt doesn’t go all the way or gets stuck, you could damage your rifle or the laser by pushing it.

Most laser bore sights, including mine, turn on once the bolt is on the back of the bore sight. While the bolt might not be shut, it doesn’t have to be for the laser to work.

While the SiteLite is my overall favorite, the Wheeler Professional laser dot is perfect for the AR-15 or other rifle. It’s durable, easy to mount, and I can turn it off to conserve battery.

Wheeler Professional Laser Bore Sighter with Magnetic Connection,...
  • DIMENSIONS: 9.17 inches L x 5.35 inches W x 2.01 inches H
  • SPECS: Class IIIR with power output of less than 5mW
  • EASE OF USE: Magnetic connection quickly and easily attaches to the muzzle of the gun and can be used on any caliber rifle or handgun

Zeroing Out

Angle your AR-15 until the laser lines up perfectly with the center of the same target. Look down your rifle scope and adjust the reticle to coincide with your laser.

Remember that it’s about precision. Take your time and use the adjustment knobs. Between windage and elevation MOA clicks, you should have your crosshairs overlapping the laser.

Take Out the Bore Sight

If you’re satisfied with your rifle scope adjustments and feel confident in the accuracy, it’s time to remove the laser. It comes out the same way it went in.

Pull back the bolt, take out the laser bore sight, and close the bolt. Without the bolt hitting the activation button, your laser should turn off automatically.

Alternative Bore Sights

While laser bore sights are common, you have options. If you’re using a bolt-action rifle, you can try visual boresighting. It’s reliable and functions like a laser, but it’s older and limited.

It has the same bore sighting process. You take out the bolt, insert it, and lock it down. If you’re a more experienced shooter, you might like the optical bore sight.

Instead of going in the chamber of your AR-15, this one goes on the end of your barrel. You’ll mount it and turn it on. An etched grid pops up that you can use for perfect accuracy.

All bore sighting has the same goal in mind. Whichever bore sight you use to zero your rifle scope, you should have precision. If you’re more of a visual person, here’s a video to help you:

Still, there’s only one way to know for sure. Putting your AR-15 to the test will tell you if your bore sight worked.

Test Your Rifle Scope

The 25-yard target shouldn’t take much adjusting with your rifle scope. Precision at that range is almost guaranteed for an average shooter with an AR-15.

However, if you used a green laser bore sight to zero at 100 yards, it’s about understanding MOA. Most rifle scopes do ½ or 1 MOA per click for a windage or elevation turret.

The Minute of Angle will ultimately affect precision. Knowing your rifle scope and MOA is just as important as setting up your laser for an AR-15.

When you’re done with your bore sight, safety always comes first. Before you mount your new rifle scope, unload your AR-15 and make sure that it’s clear with the same process.

I like to clear the chamber twice for good measure. Caution beats an accident any day. With your scope mounted, take your first shot and see how precise the laser is!

Assuming everything went as planned, you’re on your way to hunting success!


How accurate is a boresight?

Bore sighting is designed to perfect your accuracy and precision without firing a shot. If done right, a laser should be extremely accurate. They line up your scope or iron sights easily.

How far is a bore sight good for?

The main factors that affect your bore sight’s range are the laser intensity and color. Green lasers are usually more visible at a distance up to 100 yards. Red lasers aren’t as good outdoors. 

While price doesn’t always mean better, bore sight costs are generally a good indicator of quality.

3 thoughts on “How to Bore Sight an AR-15 (Explained in Plain English)”

  1. It seems like the scope is higher than the bore! So at some point the line of site will cross the the trajectory of the bullet! Making long shots too high! What do you think?

    • I normally use a 25 yard indoor range to zero my scope using standard ammo. In those cases, they call for the round to strike around 2″ higher than the scope cross hairs, depending on the caliber of the rifle, because of the distance between the top of the rifle and the mounted scope. It seems to me that the same thought would apply bore sighting at 25 yards.


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