A Boresight Blog

By Mark Butler

Boresights are awesome! These nifty little devices enable shooters to pre-align the bore of their firearm with the optics mounted atop it, whether it’s a scope, red dot or iron sights. All too often, a hunter concludes a hunting session by cleaning their weapon and storing it until their next outing. When they retrieve their weapon (usually after having transported it), they take the weapon to the range, look through the scope, and settle the reticle on the bullseye. They pull the trigger and hit a few inches to the left (or right) of the target. What happened? Well, either during the transport, or perhaps from the recoil of previous sessions, or maybe just from dropping the firearm, the sights have shifted slightly, resulting in a misalignment, and consequently, a missed shot. This is an even more embarrassing problem if a hunter goes straight to the woods and attempts to harvest an animal without ensuring their rifle is zeroed. Instead of a kill-shot, they may get an unethical gut-shot, which is a lose-lose for everyone. To avoid this issue, responsible gun owners use laser boresights.

The benefits of using a boresight are countless. Aside from the greatly improved accuracy, a boresight can save shooters a lot of money on ammunition during the live-fire zeroing process. Along with saving money, a boresight will also save time, allowing the shooter to get on paper faster. Finally, a boresight will save your shoulder from the recoil of a prolonged live-fire zeroing process – and who doesn’t want to avoid physical pain?  

A Brief History

According to opticsplanet.com, the oldest way to boresight is to remove the bolt on a bolt-action rifle and look down the bore. Position the gun so that it is pointing at your target, and then secure the gun so it won’t move. Then, without moving the gun, look through the scope and adjust the windage and elevation turrets until the reticle is centered on the bullseye. Now the weapon is boresighted, although this antiquated method is less accurate than using a laser boresight, and it likely won’t work on semi-autos, pumps, lever guns and most handguns.

In recent years, great advances have been made in the science of boresighting. Magnetic and laser boresights are the most popular and effective, methods for modern boresighting.   

Laser Boresights

In-chamber laser boresights are exceptionally easy to use. If you visit Sightmark.com and click here, customers can locate exactly which boresight they need based on caliber. There are options for pistols, rifles, shotguns and even crossbows. Once a laser boresight is purchased and delivered, it will become a staple of any credible shooter’s range bag. An in-chamber laser boresight is chambered like a regular round, and it will emit a red or green laser from the barrel of the firearm. Ideally, with a reflective target set about 30 yards away, the red laser beam will be visible. Then, the shooter merely needs to secure their weapon in place and adjust their scope until the reticle is aligned with the red laser. At that point, the shooter can retreat to 50 yards and re-center their reticle. Some shooters will repeat this process at 100 yards, though the red dot will be very difficult to see at that distance, especially in bright daylight. Again, this method will not ‘zero’ a rifle, but it will get the shots close enough so that minor adjustments are all that’s required during the live-fire.

It’s worth noting that different calibers will fire at different speeds, with varying trajectory (due to gravity). If you ‘zero’ with a .223 at 100 yards, then you must continue using that same caliber to stay on-point. Basspro.com has an excellent article on choosing the appropriate caliber for your rifle and your prey animal.

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Another benefit of a laser boresight is to quickly re-check zero. For example, if a shooter uses an in-chamber laser boresight and gets close to the bullseye, and then they shoot and get ‘zeroed’, they can document exactly where they shot from and where their point-of-impact is. Then, the following hunting season, or the following year, or whenever, the shooter can put the laser back in and verify that the laser is in the exact same spot. This will quickly get a shooter ‘zeroed’.

On Accuracy and Ammo

Now, it’s important to remember that a boresight will not make your gun 100% accurate. Live-firing is still necessary to fully zero-in a firearm. Different calibers have different weights and travel at different speeds, so not all ammunition is equally affected by factors such as gravity and wind, which changes points of impact. For your specific gun, you must choose the correct boresight for your optics. Also, you must always remember to remove your boresight before attempting to shoot – you don’t want to damage your firearm or yourself! 

Some Final Thoughts

Boresighting is a vital component of responsible gun ownership. It is just as relevant as firearm safety, cleaning your weapon and obeying the laws of wherever you’re shooting. Boresighting your weapon the old-fashioned way is still perfectly acceptable, and if that’s your speed, feel free. Most modern shooters, however, use laser boresights because they are quicker, cheaper and more reliable than any other method. If you want to join the ranks of reliable, responsible gun owners, remember to visit http://www.sightmark.com