Red dot sights are becoming more and more popular in shooting sports competitions. Sight pictures are simplified, and it allows you to stay “target focused” as you move across each target for faster target acquisition.
Any sighting system's accuracy must support the intersection of the sights and the barrel to the target. One big difference between a red dot and an iron sight system is the height distance from the sight (or dot) to the barrel’s bore axis. Most iron sights sit low to the bore axis, making them more consistent across near-to-far distances. Red dots sit higher off the bore axis, so understanding how that influences the sights at different distances is essential.
Point of aim (POA) is where the red dot appears on the target as you aim the pistol. Point of impact (POI) is where the bullet impacts the target using a consistent aiming point. Sighting in a red dot, or “zeroing,” makes the Point of Aim (POA) align with the Point of Impact (POI) at a given distance.
Red dots use a consistent measurement called “minutes of angle” (MOA) to align your Point of Aim (POA) to the Point of Impact (POI). An MOA represents 1.047 inches at 100 yards. We will round 1.047 inches to 1.0 inch for our pistol example shown below.
If your red dot’s Point of Aim (POA) is on the bullseye at 100 yards and your bullet impacts approximately three inches to the right of where you aimed, you will adjust the dot three MOA to the left. This would align the point of aim with the point of impact. (Refer to your red dot sight manual for details on how MOA increments are measured for your sight adjustments.)
You should not sight-in your pistol at 100 yards. The average target distance for USPSA and SCSA is less than thirty-five yards. It is recommended that you start at ten yards so you can see the target, keep the math simple, and then confirm and adjust your settings at further distances. Note: Your final preferred zero will probably be somewhere between fifteen and twenty-five yards.
• 100 yards = 1-inch adjustment = 1 MOA
• 10 yards = 1-inch adjustment = 10 MOAs
• 10 yards = ½-inch adjustment = 5 MOAs
Step 1. Test and adjust Point of Aim & Point of Impact at ten yards - Start at ten yards and adjust your red dot to its smallest size so you can refine your aiming point. You will be shooting three to five rounds for each test. You want your shots to group as much as possible. It is recommended that you use targets with a clear one-inch center point for aiming. Targets with one- to half-inch lines will help you adjust the zero quicker. Use the same ammunition you will compete with for consistent results.
The objective is to make consistent shots, taking as much time as you need. Practice good trigger control, aiming for consistent, accurate shots. Start at ten yards and sight your pistol’s dot on the center of your target, take three to five shots, then inspect your group and adjust your sights’ horizontal and vertical MOAs as needed.
Step 2. Test settings at fifteen, twenty, and twenty-five yards and adjust horizontal Point of Impact as needed - Only adjust the horizontal at this stage. If you drew a line from the top of the target to the bottom, your shots should track to that line at each distance. You will start to notice differences in Point of Impact (POI) elevation as you shoot the targets at each distance. The farther the distance, the higher the Point of Impact (POI). This difference is normal.
Step 3. Test and adjust vertical Point of Aim & Point of Impact using an average target distance - Choose an average distance for targets you will be shooting the most in your type of competition. Pick a distance between fifteen and twenty-five yards and set up your target. At this point, the horizontal settings should be accurate, and you will only be focused on the vertical elevation adjustment.
Tip: To quickly measure vertical settings at different distances, I like to place a line of blue painters’ tape on a target and fire several shots at the tape. You can quickly measure how high or low the Point of Impact (POI) is from the original line of tape.
Step 4. Review and confirm Point of Aim & Point of Impact settings at three, five, ten, fifteen, twenty, and twenty-five yards - The closer target’s Point of Impact (POI) will be a little low, and the farthest targets will be a little higher than your zeroed distance. You want to know how your pistol performs at each distance so you won’t be second-guessing where the Point of Impact (POI) is during a match.
Step 5. Test your settings in several practice sessions to determine what works best for you - Set up a sample stage with targets at varying distances and check your performance. You can quickly change your POA/POI using different distances to zero because you only need to change the vertical setting at the new distance.