The Ultimate Firearms Destination for the Gun Lifestyle

Bore Sight Buyer’s Guide

You don’t need a bore-sighting device. That being said, they’re nice time and ammo savers.
If you’re in no hurry, don’t mind walking back rounds from 25 yards to your zero distance, and aren’t concerned with saving, maybe, a handful of rounds, you can use your eyeball and a dot on the wall to get your scope on paper.

But if you want to save 20 to 30 minutes of range time for more constructive use, save a few rounds and have a way to easily and quickly confirm your zero after transporting, or bringing your gun out of storage, then one of these bore-sighting devices might be worth a look.

The role of a bore sighter is to speed up the zeroing process of your gun, not eliminate it. Ostensibly, the more you spend on one of these gadgets, the more time you can save by getting closer to a ballistic zero before firing a round.

Options
There are levels of complexity within the bore-sighter market. Bore alignment, ballistic drop measurement, multi-caliber compatibility … all of these things add complexity to a bore-sighting system and can affect accuracy and price.

There are two major types of commercial bore-sighting systems: optical collimators and indicating lasers. Each of these can be further broken down into magnetically mounted, arbor mounted and chambered devices. And then there’s eyeballing it.

Collimators are the most mystical, and we don’t have the time, or the college degree to explain the science behind them. Suffice it to say, a collimating bore sight is a lens, aligned perfectly perpendicular to the bore, that sits in front of your firearm’s sighting system and tricks it into thinking it’s looking at a target that is 100 yards, or more, away. Printed on the lens is a tiny reticle grid that’s presented to the optic in relation to the size of the optic it’s viewed by. Again, this is a gross simplification.

As long as the device is perpendicular to the bore, it doesn’t really matter if the lens is perfectly centered in front of your sights or scope. But it should be plumb to take advantage of the device’s holographic-like target grid when using it to calculate ballistic drop or record a zero for later confirmation. Yes, these devices are, mostly, accurate enough to help visualize bullet drop when used with a magnified optic.

The advantages of a collimator include not needing batteries, and the ability for the device to include an onboard targeting grid.

On the other hand, lasers are simple, cheap, and, in many ways, just as accurate. The cost of a laser is usually related to the amount of effort needed at the manufacturing level to align the laser to the plane of the bore or magnet that it’s mounted on. The laser’s ability to retain that setting over time also adds to its expense.

Hold
Whether we’re looking at collimating sights or lasers to provide an aiming point for our optic, we need some way of holding the device in line with the bore of the gun. Bore arbors are pretty cheap and accurate. They’re inserted in the last 3 inches of the bore and held in place with an internal, expanding collar. On the downside, these collars are usually soft metal or polymer, but people get weird when you talk about sticking things down the bore of their rifle. Being long, thin rods, they’re easily susceptible to alignment issues and damage from inadvertent bumps while in the bore. Plus, you’re going to have to keep a little baggy of caliber adapters and screws handy whenever you use it.

Magnet-mounted devices adhere to the muzzle without anything going into the bore. Their operation and accuracy is dependent on the idea that barrel crowns are machined perfectly perpendicular to the bore, and most are. Snap one on the end, and, whether it’s a laser or collimating system, you don’t need to deal with any bore adapters to use it with any caliber, from rifles and pistols to shotguns … as long as there’s a lot of ferrous metal at the barrel end.

In-chamber lasers are very small, very cheap, and sometimes accurate. Chambers aren’t always cut perfectly inline with the bore, and, even then, the devices have to be slightly undersized to fit in a wide range of chambers, introducing slop. If you go this route, you’re going to need to shell out to buy a laser for each caliber. Still, the things are usually accurate enough to get within a foot of a bullseye. Just don’t expect them to last long.

One thing to consider with all of these systems is that none of them are perfect, and all of them will get you on paper. It’s up to you to decide if you want to drop the cash on a device that’ll speed the zeroing process up. For agencies, this is a no brainer. Time is money, and one of these systems can save a unit or department serious cash when maintaining a fleet of guns and shooters. For the individual, though, the decision to buy one comes down to if you want to spend money on a device that’ll speed up (not eliminate) the zeroing process.

Rule of Thumb
One thing to consider if you’re deciding between laser and collimating systems: A laser can touch a real target, while a collimator can only project a holographic grid in front of your reticle. You can use the laser to indicate points on a target that can be measured with a ruler. This means you can accurately apply calculations from a ballistic solver to your theoretical zero.

Alternatively, use this rule of thumb with a laser to get a zero that accounts for bullet drop seen in common .22 centerfire and some .30 caliber bullets: at 25 yards, put your scope’s reticle above the laser dot about half the height of the scope’s height-over-bore measurement. This inch, or so, translates into an on-paper hit for almost any small to mid-caliber, centerfire round when used with an accurate laser system.

RECP-170900-BORESIGHTS-TESTING-007.JPG

Testing
To determine how accurate the sample devices were, we mounted each one, aligned our optic’s reticle to the indicated zero point suggested by each product, then shot a 3-round group at the center of a target 100 yards away. We then measured the distance each hit was from the device’s suggested aiming point. This offset is noted in each of the product descriptions below.

Our test rig consisted of a Proof Research Switch rifle with a stainless steel barrel chambered in .223 Remington, topped with a Nightforce ATACR 5-25×56 F1 scope. The first thing we did was shoot groups with the gun to make sure it couldn’t be blamed for any accuracy issues. It produced .37 MOA five-shot groups running Federal Gold Medal Match 77-grain SMK BTHP ammunition. No issues there.

If the device came with a case, we used it to transport the bore sighters to the range, offering the same level of care and protection from damage as an end-user might. And, all laser-based devices were bore sighted at 25 feet before zeroing at 100 yards.

Bushnell
Banner Boresighter Kit

BROWNELLS 10-22BROWNELLS 10-22

MSRP: $131
URL: www.bushnell.com
Type: Arbor Optical
Battery: n/a
Indicated POI vs. Actual POI at 100 yards
Elevation: 4 inches low
Windage: 4 inches right

Notes:
If there were ever a better case for, “If it ain’t broke ….” We found a product announcement for this kit in the June 1969 issue of Popular Science. It retailed for $25. The Banner kit we got from Bushnell a few weeks ago looks virtually unchanged from its bell-bottomed debut. The business portion is the collimating lens that projects an etched aiming grid. The grid has thick-lined crosshair, usable for coarse sighting with non-magnified optics and irons. Sighting a magnified optic lets you take advantage of the grid’s fine, 4-inch delineations at a projected distance of 100 yards. This lets you account for drop and get even closer to your range zero by applying ballistic calculations while bore sighting. Additionally, once you’ve fully zeroed, you can reinstall the bore sighter, note the location of your scope’s reticle, and use the system to confirm a refined 100-yard zero later on. Our kit came with four arbors, covering popular rifle and pistol calibers from .17 up to .45.

Pros:
Removable and replaceable arbors means the system is stored in way that’s less susceptible to damage. Damaged arbors can be replaced without tossing the whole shebang. Large objective lens work with highly magnified optics. Over 3 inches of mandrel in the bore provides good approximation of bullet path. No batteries.

Cons:
Slipping a metal arbor into a muzzle brings us visions of horrible cat sex. The unit is larger than its competitors. Lacks versatility of newer systems that can level a scope. Shorter height-over-bore of devices makes it tough to use with tall, non-magnified, AR optics. When used with muzzle devices, there’s only 1.5 to 2 inches of arbor to left for true barrel contact.

Bushnell
Magnetic Bore Sighter

BROWNELLS 10-22BROWNELLS 10-22

MSRP: $52
URL: www.bushnell.com
Type: Magnetic Optical
Battery: n/a
Indicated POI vs. Actual POI at 100 yards
Elevation: 12.6 inches high
Windage: 4 inches left

Notes:
The optical features of the Bushnell Magnetic Boresighter are similar to the Banner Boresighter. It’s an optical collimator that projects a target at 100 yards with a reticle etched on a frosted lens. The grid is a lot coarser than the Banner, and it doesn’t line up to a particularly useful measurement downrange. Near as we could tell each box was about 16 inches at 100 yards. This guy’s a little faster to set up, though, since it’s just held in place with a magnet. It’s a no-frills proposition that comes with a poorly fitting drawstring bag and a single page of instructions that haven’t been updated since they were first committed to paper, no doubt, by a tie-wearing man smoking a Camel in front of a typewriter.

Pros:
Old-school collimator still delivers on-paper hits without math or a battery. Arborless system means no chance of damage to the bore and no need for a pile of adapters to use it with multiple calibers.

Cons:
Short stalk height limits its use to sights and optics with low height-over-bore measurements. It doesn’t work well with a lower-third co-witnessed reflex sight, for instance. Coarse grid pattern makes it hard to precisely confirm zero later on. Accuracy depends on perpendicularity of muzzle end to bore.

Bushnell
Laser Bore Sighter

BROWNELLS 10-22BROWNELLS 10-22

MSRP: $43
URL: www.bushnell.com
Type: Arbor Laser
Battery: AG13 Button Cell
Indicated POI vs. Actual POI at 100 yards
Elevation: 3.5 inches high
Windage: 0.75 inch left

best-value

Notes:
Lasers, like Tang and 3.5-inch floppy disks, once really represented the future. But, we are now in the future, and lasers passed the pale of high-tech and are now truck-stop novelties, most with performance befitting their $3 price tag. Bushnell strips the arbor-mounted laser bore sighter down to its bare and most economic essentials. This guy runs on a set of button cells, and it’s simple aluminum body features a screw hole that accommodates a series of caliber-specific, expanding plastic bore locks; each secured with a tiny hex screw. Screw the bore lock into the end, shove the device into the bore, and rotate it till the bore lock expands, and the rod is held at the other end with a conical shoulder. Twist the head to activate the laser. Pointed at a bare surface 25 feet from the muzzle, you line up windage and guestimate elevation by setting your reticle above the dot about half the distance of your scope’s height over bore. And, you’re on paper.

Pros:
Small package, simple operation. Inexpensive. Works on .22 to .50 calibers with included adapters. Outstanding accuracy and a great value.

Cons:
Long rod is susceptible to bending during transport and while in use. Limited to indoor, short-range use; practical range is less than 50 yards. Red laser is almost impossible to see in broad daylight. Even then, the cheap laser emitter puts out a broad, diffuse dot at 100 yards that makes fine-tuning at distance imprecise. Laser arbor only has 2.25 inches for bore insertion.

Human Eyeball

EYEBALLvisual sight

MSRP: $0
URL: www.wikipedia.org/wiki/Human_eye
Type: Organic
Battery: Cheeseburgers
Indicated POI vs. Actual POI at 100 yards
Elevation: 8 inches high
Windage: 4 inches left

Notes:
The brain and eye are wired to find the center of a circle, and organic bore sighting takes advantage of the brain’s natural tendency to align and balance things. Remove the bolt from the rifle (and separate the upper from the lower, if you’ve got an AR) so you can sight all the way down the bore. Place the rifle, or the upper, in a rest that won’t allow it to move and sight down the bore at a dot anywhere from 25 to 100 yards away. Without moving the barrel, align the optic’s windage and elevation to converge on the same point. You’ve now got a respectable 25-yard zero, a decent place to start the ballistic zeroing process at the range. In a pinch, you can even use this system at night by perching an AR upper atop a trashcan and pointing it out a hotel window, using a distant streetlight as an aiming point. Ask us how we know.

Pros:
It’s free, easy, and accurate enough to get you on paper.

Cons:
Can be frustrating if no suitable rest is available. Uses more ammo and time than lasers and collimators since this method works best when the ballistic zeroing process begins at 25 yards and progresses to 100 yards. Doesn’t work on guns that don’t allow line of sight down the bore.

Leupold
Zero Point Magnetic Illuminated Bore Sighter

BROWNELLS 10-22BROWNELLS 10-22

MSRP: $100
URL: www.leupold.com
Type: Magnetic Optical
Battery: SR60 Button Cell
Indicated POI vs. Actual POI at 100 yards
Elevation: 7 inches high
Windage: 1 inch right

Notes:
Leupold’s Zero Point is a super-compact, durable collimating device that’s been around for more than a decade. It combines the ease of use of a magnetic attachment with the accuracy of an optical collimating lens, and the utility of a scaled reticle grid (1 grid = 8 inches at 100 yards). Leupold says you can see a downrange target, the bore-sighting grid and your optic’s reticle all at the same time, allowing you to perform a one shot zero. We found that difficult to do, but all other aspects of the device were commendable. Comes with tiny range cards to record confirmation zeros for a few gun and ammo configurations. Based on size, accuracy, and ease of use, it’s one of our favorites.

Pros:
Compact. Backlight increases ease of use in dim conditions. Tall enough for zeroing AR-mounted optics. Not caliber specific.

Cons:
Tougher to use with higher magnification scopes; the Zero Point’s grid gets tough to see beyond 15x magnification. The grid appears small and hard to use for finer adjustments when used with non-magnified, red-dot optics. Though, the grid’s bull’s eye is still discernable.

SightMark
AccuDot Laser Bore Sight – 223

BROWNELLS 10-22BROWNELLS 10-22

MSRP: $36
URL: www.sightmark.com
Type: Chamber Laser
Battery: SR754w Button Cell
Indicated POI vs. Actual POI at 100 yards
Elevation: 11.5 inches high
Windage: 3.5 inches right

Notes:
In-chamber lasers exhibit lower accuracy compared to competing types of bore sighters, but they’re the most compact and inexpensive bore-sighting devices you can get. Because the device has to fit in all chambers of a given caliber, it’s slightly undersized and will always have a few thousandths of an inch of play. They generally run on button cell batteries that can be hard to source in some localities. We found button cells online for pennies when ordered in bulk, though. Lack of on/off switch means there’s one less thing to break or fail, but taking out and reinstalling the batteries for each session usually means dropping one of the little guys and wasting time looking under furniture for the escaped cell. Like the arbor laser, set the reticle a couple inches above the dot at 25 yards, and you’ll be pretty close when you start ballistic bore sighting at 100 yards.

Pros:
Compact, inexpensive.

Cons:
Need one for each caliber. Accuracy of device is dependent on the chamber being cut square to the bore; this isn’t always the case. Weak, red laser isn’t visible outdoors in daylight. Short battery life; batteries aren’t common. Device is subject to damage as it’s fed into actions.

SiteLite Lasers
SL-150

BROWNELLS 10-22BROWNELLS 10-22

MSRP: $36
URL: sitelite-lasers.com
Type: Chamber Laser
Battery: SR754w Button Cell
Indicated POI vs. Actual POI at 100 yards
Elevation: 11.5 inches high
Windage: 3.5 inches right

Notes:
In-chamber lasers exhibit lower accuracy compared to competing types of bore sighters, but they’re the most compact and inexpensive bore-sighting devices you can get. Because the device has to fit in all chambers of a given caliber, it’s slightly undersized and will always have a few thousandths of an inch of play. They generally run on button cell batteries that can be hard to source in some localities. We found button cells online for pennies when ordered in bulk, though. Lack of on/off switch means there’s one less thing to break or fail, but taking out and reinstalling the batteries for each session usually means dropping one of the little guys and wasting time looking under furniture for the escaped cell. Like the arbor laser, set the reticle a couple inches above the dot at 25 yards, and you’ll be pretty close when you start ballistic bore sighting at 100 yards.

Pros:
Compact, inexpensive.

Cons:
Need one for each caliber. Accuracy of device is dependent on the chamber being cut square to the bore; this isn’t always the case. Weak, red laser isn’t visible outdoors in daylight. Short battery life; batteries aren’t common. Device is subject to damage as it’s fed into actions.

Wheeler Engineering
Professional Laser Bore Sighter, Green

BROWNELLS 10-22BROWNELLS 10-22

MSRP: $160
URL: www.btibrands.com
Type: Magnetic Laser
Battery: CR123
Indicated POI vs. Actual POI at 100 yards
Elevation: 2.5 inches high
Windage: 0.5 inch left

editors-pick

Notes:
The Pro Bore Sighter combines a daylight visible laser that’s accurately tuned, and housed deep inside what feels like an indestructible, rubber over-molded, body. The unit features a single control, a clicky-style flashlight power switch, and runs on a fairly common CR123 battery. It adheres to your gun barrel with a rare-earth magnet and holds on like a hungry deer tick. As long as your muzzle, or the face of your muzzle device, is square to the bore, this thing will get you on paper in less time than it takes you to find something to get upset about on Facebook. Used with a ballistic calculator, you can get within inches of the bull’s eye before you’ve even put your pants on.

Pros:
Magnetic attachment is easy to use, strong, and poses no risk to the rifle bore, and little risk to the crown as long as you keep mating surfaces clean. Works on any firearm that has a well machined, steel crown. Laser is visible in daylight when used with included reflective target. Very accurate. No caliber specific adapters to install or lose. Long battery life; CR123 batteries are widely available.

Cons:
Only as accurate as the machining on the muzzle crown. In theory, the unit’s accuracy does suffer when used with a muzzle device, though we didn’t see any issues when used with high-quality brakes on an AR. Can be troublesome with open-tine flash hiders.

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