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How to Zero a Pistol Red Dot

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In our previous article, we went over the different zero distances you could opt for when sighting in your pistol’s red dot sight. To briefly recap, your zero distance is crucial in determining how you’ll be able to use your optic, so it’s important to make sure you have the right one. 

If you didn’t already know, mini reflex sights are not only quicker to use than standard iron sights, but they also provide a much better sight picture. However, their effectiveness relies on a solid zero, so you’ll need to know how to zero a red dot sight. 

It’s a common misconception that all enthusiasts have to do is simply fix their red dot sight to their pistol and they’re good to go. As easy as this would be, it’s simply not the case. Just like a variable power optic on a rifle, your mini-reflex sight needs to be properly zeroed too.  

Though it can definitely be an intimidating task if you aren’t familiar with zeroing optics, you can rest assured that it’s much simpler than it appears. Below, we’re going to walk you through the process of setting up and zeroing your pistol red dot/mini-reflex sight:  

Classic mini RDS on Zev

Understanding Pistol Red Dot Sights  

Reflex sights use a small diode to project a reticle onto the objective lens of the optic. Depending on the model optic you use, you have the option of different reticles instead of just the basic dot that comes on most mini-reflex sights. 

Most mini-reflex sights use a standard dot reticle, but others utilize circle dot reticles or chevron patterns. While the standard dot reticle works well, other reticle styles may benefit you more. For instance, the ACSS Vulcan reticle has a large circle that sits outside of the field of view to guide you towards the 10 MOA center chevron (or 3 MOA dot), eliminating the challenge most new enthusiasts have, which is finding the reticle when they are off-center and lose the reticle in the window. 

Our guide on the ACSS Vulcan reticle goes much more in-depth with the benefits it provides, check it out to learn more. (Will provide when article is published) 

A mini-reflex sight is a smaller version of the aforementioned reflex sight. Though they can be attached and ran on carbines, usually as a backup sight, they’re specifically made for use on pistols and provide similar benefits. There are two main types of mini-reflex sights, open emitter, and closed emitter sights.  

Open-emitter sights are a type mini-reflex sight that have a front objective lens on which the reticle is projected. They’re a popular choice to use on pistols since they tend to be lighter weight compared to a closed emitter dot. Optics like our Classic Series 21mm Micro Reflex Sight, 24mm Mini Reflex Sight, and our SLx RS-10 1x23mm Mini Reflex Sight are great examples of open emitter sights.

In contrast closed emitter sights are like their carbine sized counterparts. Instead of having only one objective lens and an exposed emitter, they have two lenses and a fully enclosed emitter. Though they are bigger, they still work incredibly well. Some of the best pistol optics are the Holosun HE509T, Aimpoint ACRO, and the Trijicon RCR

Both are great options, but they have their pros and cons. For instance, open emitter mini-reflex sights run the risk of having the diode get blocked by dirt and other debris when in use. Still, they tend to have wider objective lenses, giving them a wider eye box and better overall field of view. Closed emitter sights are better for adverse conditions where dirt and other debris is likely to be around the sight since the emitter diode is enclosed in an air and watertight casing. However, the size of these optics tends to be larger and have a smaller field of view.  

While both types of optics perform similarly, they’re better for different scenarios. Ultimately, it’s up to personal preference, but for most scenarios like recreation, home defense, concealed carry, or race gun competitions, an open emitter red dot works great. If you know you’re going to be using your pistol in rougher conditions like duty, more rigorous style competitions, a closed emitter mini-reflex sight will offer more in terms of protection. Keep in mind that this isn’t a hard rule, and you should opt for the sight that works best for you.  

If you’re having trouble deciding on the best red dot sight for your pistol, our red dot buyer’s guide can help point you in the right direction. 

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Preparing Your Optic for Zeroing 

There are a lot of different mini-reflex sight options available for handguns, and most use different mounting footprints. An optic’s footprint is the type and shape of the bottom of the optic and is used specifically for mounting onto the slide of a handgun. Not every pistol red dot sight is compatible with every pistol. For instance, some sights, like our SLx RS-10 1×23 Mini Reflex Sight, have a Docter/Noblex footprint, while other optics, like the Trijicon RCR, have an RMR footprint.  

Since not all optics have the same mounting footprint, there are adapters you can use that allow the optic to mount securely to your pistol. For example, GLOCK uses their proprietary MOS mounting system, which uses adapter plates in multiple footprints ensuring that their slides will fit most of the common footprints available in the mini reflex category. GLOCK also provides these MOS plates When you purchase your firearm so you can mount your optic. 

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Mounting Your Pistol Red Dot Sight 

With your optic chosen, you’re ready to mount it to your optic, so long as you have the proper adapter. Like we said before, different optics have different ways of mounting. Open emitter sights, for example, most often have two screws that thread through the top/open portion of the sight, into the slide of the pistol. Closed emitter sights can’t mount this way because of the way they’re designed. Instead, they often have a specific mounting plate to attach to.  

When installing your mini-reflex sight, or the mounting plate, we recommend you use thread locker to keep your screws from backing out when in use. Choosing the right mounting plate ensures proper alignment, preventing skewed positioning. Also, make sure you follow the manufacturers torque recommendations. To lose and the optic my detach unexpectedly. To tight and you run the risk of stripping or snapping. 

Bore Sighting 

Bore sighting is when you look down the barrel from the rear of the pistol to align the bore of your firearm with your firearm and adjust your sight to match that image. While this isn’t necessary to sight in your optic, it will save you money on ammunition because this process reduces the number of rounds needed to sight in your optic.  

On rifles, like bolt guns and AR-15s, this process is easy since you can either take the bolt out of your rifle or separate the upper from the lower receiver. It’s not so easily done on pistols, since the barrel sits within the slide which has no rear opening to see through the barrel. This is where a boresight laser comes into play.  

A boresight laser fits into the chamber, or muzzle, of your pistol and projects a laser beam onto your target to make it easier to align your sights properly. Keep in mind, this doesn’t eliminate the need for live-fire to zero your optic in. Lasers aren’t affected by gravity, but bullets are, so you’ll need to adjust for this with live rounds. 

COM Trijicon Zev Surefire 09

Sighting in Your Optic 

With your optic securely attached to your pistol, you’re ready to get it sighted in. After you’ve adjusted based on the bore sight or your initial test group, you can make adjustments to zero in your pistol red dot sight.  

Your optic will have two adjustments, one for windage and the other for elevation. Keep in mind that the markings on the adjustment screws refer to the direction that you are adjusting the bullet impact, not the direction you are adjusting the reticle. If you are impacting high and right of your point of aim, you need to make adjustments down and left. 

Now that you’ve adjusted your sight, fire another test group to see where your bullets impact. Make additional adjustments if necessary and repeat the process until you’re satisfied with the results. If it’s your first-time sighting in an optic, it may take a few tries to get the result you want. This is perfectly okay, take your time and try not to over adjust your elevation or windage.  

Once your bullets are impacting where your reticle sits, you have zeroed your pistol optic. Now that it’s zeroed, it’s important to not make any additional adjustments. Fortunately, on most pistol red dot sights, the adjustment knobs sit flush with the optic itself or require a specific tool to adjust them. This will minimize the risk of accidentally adjusting your optic’s zero. While not common on mini-reflex sights, some optics come with caps that go over the windage and elevation knobs to keep them covered.  

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Wrapping it Up 

With the incredible number of benefits red dot sights provide to the firearms they’re mounted too, it’s no surprise that they’ve become one of the go-to upgrades enthusiasts make to their handguns. Still, you can’t receive any of these benefits if your optic isn’t zeroed in properly, and there’s a lot to consider with a pistol red dot.  

Now, that isn’t something that you have to worry about. Our article on pistol red dot zero distances goes more in-depth on how zero distance will affect your performance. We highly recommend you look at it before you zero your optic, since different distances are better for different purposes.

Apart from a properly zeroed red dot sight, other accessories can enhance your pistol’s versatility and performance. Check out our article on choosing the best pistol light for concealed carry to see how you can further enhance your pistol’s performance.