Zeroing is literally one of the most important thing we need to accomplish with our rifles and #spacegun pistols. There is much talk around the technique to accomplish this but there is one way that is easy and fast.
First, determine the desired zero distance.
This will vary by rifle, optic, caliber, and most importantly purpose of the firearm. Many people with AR15 rifles use either a 100, 200, or 300 yard/meter zero. Rather, many people claim to use those ranges but most use the near zero distance on either 25 or 50-yard target. Yes, I am talking in yards here because most people on this page are not using meters.
Now, to save yourself time, you can use a borelight or something like the Telluric Group Small Arms Collimator. There are lasers available in every price range and should be part of your tool kit. Doing this step will put you at the very least on paper at 25/50 which will save you rounds and frustration. Ask me how I know.
Regardless of borelight or not, it’s time to shoot bullets. Get into the most comfortable and stable position possible. One that you can duplicate easily. For you Army folk, take off your kit. Yes, the book says so. Consistency and stability are the most important aspects of this task. The target should be something with a defined aiming point, not something that is kinda where I want to aim, or center ish. I use the new Army Zero target since it was designed for this exact thing vs the old school one that was designed by an idiot.
In theory, your first rounds should land on the paper. I shoot 5 round groups as a rule until I confirm the zero. Here is where it gets hard. If you have a decent skill set your group at 25 should be less than 1 inch or 4 Minutes of angle. At 50 you should be below 2 inches (4 MOA) If your group is larger and you are on paper don’t touch anything. Get your group smaller. If you don’t have the skill set to do that I suggest dropping that $600 class and attending an Appleseed Event. Assuming you have an acceptable group the easy part starts.
Measure the distance vertically and horizontally from your impacts to the desired Point of Impact(POI).
Those inches convert to MOA easily. For our purposes, ¼ inch at 25 is 1 MOA, ½ inch at 50 is 1 MOA and 1 inch at 100 is 1 MOA.
You sighting system moves in some unit of measure, most are in MOA. Many of them are in ½ minute clicks. Some are ¼ minute and some are in 1 MOA. It is something you should know. Irons on rifles are a different story and are effected by sight radius so there is another number you need to know. Once you know the adjustment per click you simply convert the minutes you need to move into clicks.
2.5 inches high
.5 minutes per click
5 clicks down
Apply this same technique for any needed horizontal distance.
This technique works on any target you can aim and print on. You can do it with a blank sheet of paper with a drawn dot or square. A grid makes it easier but isn’t needed. Inches, Minutes, Clicks (IMC) is taught in some form or another across the country and is a tried and true technique. Once I get the desired POI, I confirm the zero with a 10-round group. This will give you a very accurate confirmation of the group as the barrel heats and give you an idea of what your weapon will do as you apply pressure to it. I had an M4 once that shifted 4 MOA as it heated up over 10 rounds if it was below 40 degrees. If you zeroed it cold and kept it cold the zero held. After 5 rounds, you could track the shots across the paper at 500. Unfortunately, the people scoring at the Canadian Forces Small Arms Concentration got to watch it too. Nothing like an international audience while learning about a rifle.
Once I have confirmed the near zero CONFIRM at the desired distance. In theory and on that cool app or webpage a 50 yard zero is a 200 yard zero. It is not. The Army swears that a 25 meter Zero is also a 300 meter zero and we all know that isn’t true. Take the time and go to distance. You will be glad you did. Besides a 1 Inch group at 100 is awesome and a 1 inch group at 25 is unimpressive.
The last step is to confirm the zero adding one piece of kit at a time. I add vest and shoot a group, add helmet, shoot a group. If I zeroed in soft ear pro I also confirm in hard ear pro also.
You can’t move on to cool things unless you have a zeroed gun. I don’t know of a single class or instructor that doesn’t have people confirm zeros in some way before moving on. You should show up to the range with either a confirmed zero or to get a zero. Close enough isn’t. It’s a mundane task that is worth the time.