How to Bore Sight a Rifle: Complete Step-by-Step Guide

You just mounted a new optic. You don't want to burn through a hundred dollars' worth of ammunition trying to find your paper target at 25 yards. That's where bore sighting comes in — and if you're doing it right, you'll save yourself time, ammo, and a lot of frustration before you ever touch off your first cold bore shot.

Bore sighting is the process of aligning your optic with the rifle's barrel without firing a single round. It's not a substitute for a full live-fire zero, but it's the fastest way to get your optic in the ballpark so your first rounds at the range actually hit something close to where you're aiming.

What Is Bore Sighting — and Why Does It Matter?

When you bore sight, you're looking through the barrel of the rifle at a target and adjusting your optic until the crosshair or dot appears centered on the same point. The logic is simple: if the barrel is pointing at a specific spot on the target and your optic is aligned with that same spot, your point of impact will be much closer to point of aim than it would be with a random guess.

Here's what you get out of bore sighting properly:

• Drastically reduced ammunition waste — Instead of 20 rounds to find your zero, you might find it in 3-5
• Faster range trips — Less time adjusting, more time shooting
• Less wear on your barrel — Fewer rounds before you're on paper
• Better for optics with limited adjustment range — Some red dot mounts have very little elevation or windage travel. Getting close first means you won't max out your adjustments before finding zero

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Method 1: Optical Bore Sighting (Best for Beginners)

An optical bore sighter is a device that inserts into the chamber or barrel and projects a laser dot or reticle pattern down the bore. You mount your rifle in a vise or secure rest, look through the bore sighter at a target, and adjust your optic until the dot is centered on the same point. This is the most accurate DIY method and the one we recommend for anyone who shoots regularly.

What You Need:

• Optical bore sighter (laser or collimator style)
• Stable rifle rest or vise
• Target with a defined center point
• Your rifle with optic mounted

Steps:

1. Set up your rifle in a stable rest. A rifle vise or a solidly braced sandbag rest works. You want zero movement while you're adjusting the optic.
2. Insert the bore sighter into the chamber (or muzzle, depending on the model). Most laser bore sighters thread into the chamber like a dummy round. Make sure it's seated properly — if it's not making contact, the laser won't be accurate.
3. Place your target at a measured distance. 15-25 yards is ideal for bore sighting. Close enough that you can see the dot clearly, far enough that barrel droop doesn't create a misleading point of aim.
4. Look through the bore sighter and locate the dot on the target. Without moving the rifle, note where the dot appears relative to the center of the target.
5. Adjust your optic's windage and elevation. Use the adjustment turrets on your optic until the reticle or dot is centered on the same point as the bore sighter's laser. Most optics use clicks — note how many clicks you're applying so you have a reference.
6. Remove the bore sighter and verify. Don't fire yet — just confirm that when you look through the bore from the same position, the optic and barrel are pointing at the same spot.

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Method 2: Visual Bore Sighting (No Special Equipment)

No bore sighter? You can do a rough visual bore sight with just your eyes — though it's less precise and works best for getting on paper at 25 yards before moving to a proper zero.

Steps:

1. Mount your rifle in a stable rest.
2. Remove the bolt or ensure the chamber is empty and clear. Safety first — never look down a bore with ammunition present.
3. Look through the barrel from the chamber end toward your target. Yes, it feels weird. It works.
4. Identify a reference point — a spot on a distant target or object that the bore is pointing at.
5. Adjust your optic until the reticle or dot is centered on the same reference point.
6. Verify and proceed to live fire.

This method is inherently less precise because your eye isn't positioned at the bore's optical center the way a bore sighter is. Use this only as a last resort before heading to the range.

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Method 3: At-the-Range Bore Sight (Without Removing the Barrel)

Sometimes you need to bore sight at the range itself — maybe you don't have a bore sighter, or you want to verify your zero after travel or transportation. Here's the practical field method:

1. Set up at 25 yards. Place a target with a clear center point — a paper target with concentric circles is ideal.
2. Fire a single round at the target center from a rested position.
3. Without adjusting the rifle, look through a bore sighter or the bore itself to see where the barrel is actually pointed versus where your shot landed.
4. Adjust your optic to bring the point of impact toward the point of aim.
5. Fire another round to confirm.
6. Repeat until you're on target, then finish your zero at your intended distance.

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How to Choose the Right Bore Sighting Tool

Not all bore sighters are equal. Here's what separates the useful ones from the gimmicks:

Laser Bore Sighting vs. Collimator (Optical)

Laser bore sighters project a real laser dot down the bore. They're accurate, affordable ($20-$60 for a decent set), and work across multiple calibers with interchangeable inserts. The tradeoff: they depend on battery power and can shift if the insert isn't seated firmly.

Collimated bore sighters use an optical element to align your eye with the bore axis without a laser. These are more accurate in ideal conditions but harder to use in bright light and require good eye alignment. Popular in precision shooting circles.

Key Features to Look For:

• Caliber-specific inserts — A bore sighter that works across multiple calibers is more versatile
• Stable battery life — Laser bore sighters are only as good as their batteries. Carry spares
• Secure chamber fit — Loose fit = inaccurate results. Look for solid threading engagement
• Elevation and windage adjustment on the unit — Some bore sighters have their own adjustment screws to fine-tune before you touch your optic

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Common Bore Sighting Mistakes to Avoid

1. Skipping the Bore Sight After Mounting New Optics

Even if you're re-mounting an optic you've zeroed before, you should still bore sight after remounting. The act of removing and remounting can shift your zero by several MOA — especially with廉价的 mounts that don't return to exact same position. Don't assume — verify.

2. Not Checking Your Bore Sight's Accuracy

Before you trust your bore sighter, verify it against a known zero. Bore sighters can come from the factory out of alignment. Put a bore sighter in a rifle you know is zeroed and see if the bore sighter's dot appears where it should. If it doesn't, you know to account for the offset.

3. Bore Sighting at Too Short a Distance

At 10 yards, even a tiny misalignment translates to a huge point of impact error at distance. 15-25 yards is the sweet spot for initial bore sighting. Close enough to see clearly, far enough that minor errors don't produce wild POI shifts.

4. Thinking Bore Sighting Replaces Live-Fire Zeroing

Bore sighting gets you on paper and in the ballpark. It does not replace a proper zero at your intended distance. After bore sighting, always finish with a live-fire zero at the distance you plan to shoot — whether that's 25 yards for an AR-15 or 100 yards for a precision rifle.

5. Moving the Rifle Between Bore Sighting and First Shot

This one's obvious but happens more than you'd think. Once you've bore sighter and you're walking to the firing line, be careful not to bump the optic or the rifle rest. Any shift after bore sighting invalidates the alignment you just did.

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Red Dot Sights and Bore Sighting: A Perfect Pair

Red dot sights are among the most bore-sighter-friendly optics because of their unlimited eye relief and wide field of view. Unlike magnified optics, which require precise eye alignment, a red dot can be bore sighted quickly and then confirmed with minimal live ammunition.

If you're mounting a red dot on an AR-15, pistol, or PCC, bore sighting is especially valuable because:

• Many modern red dot mounts (like RMR or RMSc pattern) have limited adjustment range
• Getting on paper at 25 yards in 1-2 rounds instead of 15+ saves real money
• Red dots are often used for close-range work where you need a zero fast and don't want to waste a magazine finding it

For AR-15 builds and PCC setups, a quality red dot sight like the 1X40 Red/Green Dot Combo is an excellent optic to pair with proper bore sighting technique. Its 5 MOA dot is precise enough for target work at distance while being fast to acquire for close-range transitions.

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Step-by-Step: Bore Sight Your AR-15 in 5 Minutes

Here's the practical abbreviated version for AR-15 owners who just mounted an optic and want to get to the range:

1. Install your optic and mount — Make sure the mount is torqued to spec. Check that the optic is centered in the mount if using a riser or offset.
2. Insert laser bore sighter into the chamber (ensure rifle is unloaded, chamber clear, magazine out).
3. Place target at 25 yards. Turn on bore sighter laser.
4. Adjust optic until red dot is centered on the same point the laser hits on target.
5. Remove bore sighter, load, fire 3-round group. You should be on paper and close to zero. Adjust from there.

The entire process takes about 5 minutes and can save you $30-50 in ammunition over brute-force zeroing.

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Frequently Asked Questions

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• Tactical Accessories — Browse All
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• AR-15 Accessories Complete Guide

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Editor's Note (Updated on April 9, 2026): Military Overstock recommends always completing a full live-fire zero after bore sighting, regardless of how accurate your preliminary alignment appears. Bore sighting saves ammunition and time — it doesn't replace the confirmation of actual point of impact at distance. Stay safe at the range.

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