How to Zero a Pistol Mounted Optic

I often get asked for tips on how to zero a red dot on a pistol. Students ask about it in class, and friends ask about it at the range. So here is the process I use, along with the tips I’ve picked up along the way.

Shoot, Measure, Adjust, Repeat

The process is simple, and it’s pretty much the same no matter what kind of firearm the optic sits on. First, pick a distance for the zero. Next, shoot a group at the same point of aim on the target. Then find the center of the group and note the difference between the point of aim and the point of impact. If they don’t match, adjust the optic, shoot another group, and repeat. In short: shoot, measure, adjust, repeat. Even though the process isn’t complex, it isn’t necessarily easy. That’s especially true with a pistol.

Before we start, here’s where I land: I zero every pistol I own at 25 yards. Not to worry if that sounds out of reach today. The tips below get you there one step at a time.

Tip #1: Zero a Pistol Red Dot in Stages: 5, 10, Then 25 Yards

One of the nuggets I took away from the Red Dot Essentials course at KR Training is that the zero distance matters less than most folks think. Stopping at 10, 15, 20 or 25 yards is part preference, and it’s often dictated by skill. What matters most is that you have a zero and you know your holds. Don’t worry about the holds right now, though. Those come with time and a bit of practice.

Me? All my pistols wear a 25 yard zero, and so do the pistols of most instructors and skilled competitors I know. The longer distance is less forgiving, which is the point. For example, an aiming error that moves the group a fifth of an inch at 10 yards moves it half an inch at 25. In other words, a zero confirmed at 25 yards is a more precise zero.

Three Stages: On Paper, Coarse, Fine

Getting there takes three stages. First, 5 yards is the on-paper check, which makes sure the shots land on the target at all. Next, 10 yards is where the coarse adjustments happen. Finally, 25 yards is where the fine-grained refinement happens. I sometimes skip the 5 yard check, but I shoot several thousand rounds a year. My students, and most folks, should start at 5.

For some shooters, 10 yards is the limit for now, and that’s fine. A 10 yard zero works. In fact, when I started with pistol red dots, I stopped at 10 yards. The longer zeros required more pistol shooting skill than I had at the time. I also used that zero successfully for a long time. Once your groups at 25 yards are tight, move the zero out.

Tip #2: Get a Pistol Rest

Most folks aren’t very good at shooting a pistol. I’m not trying to be harsh, but it’s the truth. Perhaps you are better than most. Even so, get a pistol rest. It doesn’t have to be an expensive one. For instance, I use an ultra basic MTM plastic pistol rest that runs about $20.

That small investment saves me a ton of time and frustration. It takes most of the human error out of the equation. The rest gives the front of the pistol a sturdy surface, so the sight barely moves when the shot breaks. As a result, there’s less chance of shooting low and left (or low and right for left-handed folks), and the groups get tighter. Don’t think you need one? Cool, don’t get one. However, you may want to rethink that if putting every hole into a one inch square at 5 yards isn’t a walk in the park.

Tip #3: Pack the Tools to Adjust a Pistol Mounted Optic

Trust me, it’s incredibly frustrating to reach the firing line and find the right tools aren’t in the range bag. This one is a no-brainer. Of course you should have the tools for a task when it’s time to do the thing. Yet I’ve been in that spot myself. I’ve also lent my tools to countless other folks at the range who found themselves in the same spot.

Tip #4: Use a Target Designed for Zeroing

The right target makes it much easier to zero a pistol red dot. Most public ranges sell targets designed for zeroing optics, but that isn’t guaranteed. Basically, we want a target with a grid. The grid makes it easier to measure the vertical (elevation) and horizontal (windage) distance between the point of aim and the point of impact. A good zero target also has several high-contrast aiming points, which makes aiming at the same spot every time easier. Shoot-n-see style targets work well too, since they let you see the impacts without retrieving the target between shooting and adjusting.

As a bonus tip, I prefer zeroing optics at indoor ranges. They generally have target carriers that send the target to a specific distance and bring it back. That means no calling or waiting for a ceasefire to check the target or move it, which makes the whole process much faster.

Tip #5: Zero With the Ammo You Plan to Use for “Serious Purposes”

This tip comes from my mentor, Karl Rehn, the owner of KR Training, where I’m on staff as an assistant instructor. He added it in the comments the day this post went up, and I follow it. Zero the pistol with the ammo you plan to use for “serious purposes.” If it’s a competition gun, zero it with your match load. If it’s a carry gun, zero it with your defensive load.

Why does it matter? Different bullet weights and velocities land in different places. Say you zero with 115 gr range ammo at 10 yards and compete with 147 gr subsonic loads. If you never check the zero at 25 yards, you may be surprised to find your point of impact isn’t where you thought it was. At 5 yards it won’t matter much. At 25 yards it will. I covered the same idea for rifles in zeroing optics for supersonic and subsonic ammo.

How to Zero a Pistol Red Dot, Step by Step

The five tips above are like cheat codes that make the process easier and faster. For the process itself, my students start with the target at 5 yards. This is the on-paper check. Fire one or two shots at a grid intersection, away from the big bright aiming points and the edge of the target. The goal is to make sure the red dot isn’t way off.

What’s “way off”? If the impact is an inch or more left or right of the point of aim, the windage is way off. If the impact is at the point of aim or higher, or more than two inches below it, the elevation is way off. In both cases, a big adjustment comes first. On the other hand, if the impact is about an inch below the point of aim, the optic is close enough to move on to 10 yards.

Coarse Adjustments at 10 Yards

Next, I send the target to 10 yards, where the coarse adjustments happen. With the pistol on the rest, I aim at one of the high-visibility aiming points and take three to five very slow shots. The goal is to make each shot as close to perfect as I can. That means pressing the trigger slowly so the break surprises me. There’s no need to rush. A flier makes it harder to find the center of the group, so if I notice one, I fire an extra shot. Then it’s time to measure the distance between the point of impact and the point of aim and adjust the optic.

Tip #6: Count Your Clicks (About 10 per Inch at 10 Yards)

Most pistol optics move the point of impact 1 MOA per click. The Trijicon RMR and SRO, the Leupold DeltaPoint Pro and the Holosun 507C all list 1 MOA per click. Since we’re dealing with angles, how far one click moves the impact depends on the distance to the target. At 100 yards, one MOA is roughly 1 inch. At 10 yards, it’s roughly a tenth of an inch.

So at 10 yards, it takes about 10 clicks to move the point of impact 1 inch. Half an inch? Five clicks. At 25 yards, one MOA is about a quarter of an inch, so roughly 4 clicks move the impact 1 inch. That’s why the fine-tuning at 25 yards goes quickly once the coarse adjustments at 10 yards are done.

Another bonus tip: check the labels on the optic or the manual to confirm the click value. Don’t assume. Confirm. If your optic moves ½ MOA per click, double the clicks (about 20 per inch at 10 yards). If it moves 2 MOA per click, halve them.

Tip #7: Confirm Every Adjustment With Another Group

Don’t trust that the angle math and click counting got you the zero you’re looking for. If you made an adjustment, shoot another group. We may have overcorrected, measured wrong, miscounted the clicks, or made some other mistake. We are human, after all.

Moving Your Pistol Red Dot Zero Out to 15 and 25 Yards

Once you’re happy at 10 yards, you can stop there. Or move the target out to 15, 20 or 25 yards and repeat the process. Where you stop is part preference and often comes down to skill. I finish at 25 every time. If you plan to finish at a longer distance, don’t spend much time fine-tuning the elevation at each step along the way.

Why not? With a longer zero, the point of impact at closer distances sits slightly below the point of aim. How far below depends on the distance between the center of the optic and the bore of the pistol, which we call height over bore. It also depends on the zero distance. So up close, the gap between aim and impact is smaller with a 15 yard zero than with a 25 yard zero. For more on how zero distance plays out, see different zeros for different heroes.

When to Move a Pistol Red Dot Zero Out

Once again, there’s no shame in sticking with a 10 yard zero at first. When your marksmanship improves and you can shoot tight groups at 15 and 25 yards, move the zero out. Until then, a 25 yard zero is likely to be a frustrating exercise, if not a futile one. If you’re still deciding whether a red dot belongs on your handgun at all, I laid out the pros and cons of using optics on handguns. And if you want to go deeper, I wrote about the Outrider pistol-mounted optics instructor course.

Final Tip: Have Fun (and Be Safe)

Zeroing a pistol red dot takes a box of ammo and some patience, not magic. Get on paper at 5 yards, adjust at 10, and fine-tune at 25 when your skills allow. Use a rest, and zero with the ammo you’ll actually use. Then go practice your holds. Have fun, and be safe!