How to Bore Sight a Rifle for Optimal Accuracy

If you’re a hunter, interested in self defense, or even just a recreational shooter, you know the importance of having an accurate rifle.

Even a tiny miscalibration between your scope and the rifle’s barrel can mean the difference between hitting your target and missing completely.

If you’re looking to improve your accuracy when shooting, then learning how to bore sight a rifler is a great place to start.

Bore sighting is the process of aligning the barrel of your gun with the sights or scope without having to fire a shot.

Bore sighting a rifle is an important first step in ensuring optimal accuracy, followed by zeroing your rifle, whether it’s a firearm or air rifle.

Zeroing a gun without first bore sighting it is an exercise in frustration if you don’t get lucky.

So, let’s get into it!

What Is Bore Sighting?

Bore sighting is the process of aligning the sights of a firearm with the bore of the weapon.

This is typically done before zeroing the weapon, in order to save time and ammunition.

Bore sighting is a useful technique for setting up a new scope or for checking the accuracy of a rifle that has been moved or stored for an extended period of time.

While bore sighting will not guarantee that a rifle is perfectly accurate, it can help to ensure that it is close.

Bore Sighting Safety Tips

When handling firearms, it is always important to take the appropriate safety precautions¹.

This is especially true when bore sighting, as there is a risk of harming both yourself and those around you.

To help avoid accidents, it is important to follow some basic safety rules.

First, make sure that the firearm is unloaded before proceeding. This means removing the magazine then clearing the chamber, checking it with both your eyes and a finger to make sure it’s empty.

Next, ensure that the barrel is free of obstructions.

Finally, make sure that the target is in a safe location – for example, down range at a firing range.

By following these simple steps, you can stay safe while bore sighting.

How to Bore Sight a Rifle Using a Device

There are many different ways to approach the bore sighting process, but one of the simplest and most effective methods is to use a bore sighting device.

Note that it’s important to have a solid base to hold your firearm in place regardless of the method you use to sight in your rifle.

You can use sandbags but the more stability you can get the better, so a shooting rest or gun vice is preferred.

Laser Bore Sighter

One relatively simple method is to use a laser bore sighter, such as the EZshoot Bore Sight shown above.

This device projects a beam of light from the barrel of the rifle, allowing the shooter to see where the bullet will strike at various distances.

Bore sighters are available in a variety of different models, but the basic process is generally the same.

There are two basic types of laser bore sighters:

1. Ones that resemble cartridges and are chambered the same way as a live round
2. Ones that are inserted into your firearm’s muzzle, which can typically be used on a large variety of firearms

Also, keep in mind that lasers travel perfectly straight while projectiles are affected by gravity.

To bore sight a rifle using a laser bore sighter, follow these steps:

1. Check then double check that your weapon is clear and that no live ammunition is around (it has a tendency to teleport into your gun when you’re not looking)
2. Place or hang a target at a known range (the farther the better, though you can boresight at ranges as low as 15 yards)
3. Install the laser bore sighting device into your firearm
4. Secure the rifle in your shooting rest
5. Turn on the laser
6. Aim the laser dot at the center of a target
7. Adjust the sight’s windage and elevation controls so the crosshairs are aligned with the dot
8. Don’t forget to remove your laser bore sighting device once you’re finished!

This should get your windage alignment perfect.

Because of the ballistic nature of rifles, the elevation alignment will probably be off. If you’re boresighting at short ranges the adjust the elevation upward to compensate for the scope’s height over bore.

If you’re sighting the bore at 50 yards or so, this technique will get you closer on target.

You can either calculate the bullet’s arc with a a ballistic calculator and use that data to compensate or trust that you’re close enough and continue to zeroing with live ammo.

After following these steps, you should be able to get right on target with only a few shots!

Collimator Bore Sight

One of the most reliable ways to bore sight a rifle is using a collimator boresighter like the one by Bushnell.

These work similarly to a laser bore sighter but don’t require batteries and you don’t have to worry about misaligned laser diodes.

Optical collimators consist of a device with a graph that installs in your rifle’s muzzle and an arbor that anchors the grid to your weapon’s bore.

Collimators are a classic method for sighting in scopes and don’t require the rifle to be held still.

However, unlike laser bore sighters, they cannot be used with iron sights!

1. Make sure that your rifle is clear and safe
2. Attach the collimator to the muzzle of the rifle with the properly-sized arbor. It’s best to align the grid’s lines so they are at the same angle as your scope’s
3. Look through the rifle’s scope at the grid
4. Center the crosshairs with the center line of the grid
5. Remove the collimator from the muzzle and take your rifle to the range to test-fire it
6. (Optional) Once your rifle has been zeroed, reattach the collimator and note down the distance between the center of the grid and your crosshair’s new location

By following these steps, you can bore sight your firearm quickly and easily, ensuring that your shots are on target as soon as possible.

And, if you follow the optional step, you can check your firearm’s zero after it’s been in storage or following a nasty drop without having to head to the firing range!

How to Bore Sight a Rifle Without a Device

Collimators and laser bore sighters are excellent devices for easily bore sighting your rifle.

However, they do require purchasing a device, so you may find yourself having to bore sight without one.

Fortunately, there are alternate methods you can try if you don’t have one.

With a little patience, you can bore sight your rifle without any special equipment. 

Look Through the Barrel

The “look through the barrel” method is one of the easiest ways to bore sight a rifle and can be done without buying anything².

It can be done in your home, though you’ll want to use the longest sightline you have in your house.

All you need is a secure rest, something you can hang freely, and your rifle.

However, this method is not the most precise one.

Here is how to do it:

1. Hang a small weight using a piece of string so it can swing freely and let it settle so the string is perfectly up and down
2. Remove your rifle’s bolt, separate the action halves, or do whatever you can so you can look though the barrel from the rear
3. Put the barreled portion of your firearm on the sandbags or in the rest, pointed at the hanging weight
4. Look through the barrel and move the firearm so the weight is centered in the bore
5. Look through the sights
6. If you’re using a scope, rotate the barreled action so the sight’s vertical line is aligned with the string
7. Adjust the scope’s windage and elevation to center on the weight
8. Adjust the elevation upward to compensate for your sight’s height over bore

Bore sighting with this method should get you close to your bullseye, saving you time and ammunition when you head to the range.

Identify the Mechanical Center

This is the least accurate method for bore sighting your rifle but, unless your sights or scope mount are too far out of alignment, it’ll get you closer to on-target than just relying on luck.

The first step is to identify the middle of the sight’s mechanical adjustment range.

Many iron sights have this marked, making it easy. Otherwise you’ll need to eyeball it.

With a scope, you need to know how many clicks of alignment your optic provides.

If your scope’s manual doesn’t include this information then you can calculate it by dividing the scope’s maximum adjustment range by its adjustment click value.

As an example, if your scope has an adjustment range of 100 MOA and adjusts 1/2 MOA per click, your scope has 200 clicks worth of mechanical adjustment.

So, if you adjust one of the turrets until it’s maxed out then click back 100 times, that turret should be centered. Repeat with the other turret.

If your scope’s mount is parallel to the bore then you should be closer to the bullseye than some scopes come from the factory.

However, some scope manufacturers (such as Vortex³) center their scopes at the factory, so you may not be able to use this method.

Also keep in mind that this is a method of last resort and won’t truly bore sight your rifle.

Final Thoughts

Bore sighting is the process of roughly aligning the sights of a firearm with the barrel.

There are several different methods of bore sighting, but the most common is to use a laser bore sighter.

You can learn how to bore sight a rifle by yourself with a few simple tools, or you can take your rifle to a gunsmith or shooting range and have them do it for you.

Bore sighting a rifle is a simple and effective way to improve your accuracy.

However, it is important to note that bore sighting should only be used as a starting point, as there may still be some minor adjustments that need to be made at the range

But by taking the time to do this, you can be more confident that your shots will be on target.

Give it a try next time you bring a new gun to the range or need to check if your rifle’s optic has shifted!

FAQs

Resources

1. https://mgs.edu/the-4-cardinal-rules-firearm-safety/
2. https://www.snipershide.com/shooting/threads/best-way-to-bore-sight-before-going-to-the-range.6899361/
3. https://www.eurooptic.com/PDF/vortex-viper-rifle-scope-manual.pdf