I recently picked up a new “main” optic for my precision rifles, an Athlon Cronus BTR Gen 2 4.5-29×56 and so far I like it a lot. While I intended for it to end up on my 308, the realities of the ammunition situation mean that I’m shooting a whole lot more 22LR these days through my Tikka. So, for the time being, the Athlon Cronus has replaced the Vortex Strike Eagle where it will get a lot more use.
I casually zeroed the scope at 25 yards and started moving the target back and forth up to 50 yards, the limit of my closest range. When I moved the target back to 50 yards, I way overestimated the holdover. That got me thinking…
What is the right zero for a 22LR precision rifle?
I zeroed mine at 25 yards because that’s where I’d shot a lot for casual marksmanship usage during Appleseed events, and it’s the most common available distance nearby. I really hadn’t thought much about it beyond that.
So I asked around the Everyday Marksman Discord server, and 25 yards was also the most common answer for a variety of reasons. Answers ranged from Appleseed to being the furthest distance to be able to see impacts.
I searched around the web, and kept seeing 50 yards come up as another common option, but without any real explanation why. So I decided to do some experimenting and calculating, and came up with about 35 yards as a great all-around zero for a precision 22LR.
Centerfire Rifles and the 100 Yard Zero
I’m fully aware that there are many different schools of thought when it comes to the “right” zero for a centerfire rifle. I’ve written a lot about point blank zeros as a fantastic combat method, or something like the Sniping 4th Generation idea. Using a zero where you can leverage the ballistic path of the bullet above and below the point of aim is smart when your target is relatively large- but we’re talking about precision shooting here.
From my observation, though, the vast majority of precision rifle shooters utilize a 100 yard (or 100 meter) zero. There’s a reason for this, as I believe in a certain amount of “zen” that comes with knowing that you only ever have to dial or hold “up” regardless of the distance.
I ran numbers on both 77gr SMK for a an AR-15 as well as 175gr SMK from a 308 and came up with about the same result. Here is an example of the drop chart for the 175gr SMK 308 at 2650 FPS done in 5-yard increments.
Pay particular attention to the third column, which indicates the drop in milliradians. You’ll notice that as you move away from the muzzle, the bullet’s arc moves upwards to “kiss” the line of sight right around 60 yards.
From there, the arc rides the line of sight until about 120 yards, where it begins descending along the normal ballistic curve.
With a 100-yard zero, there is never any “hold under.” You only ever dial upwards or hold over. In contrast, I also tested a 200 yard zero, which resulted in a -0.6 mil hold under at this same stretch of 60 yards to 120 yards.
The 77gr SMK demonstrated the same ballistic behavior, a 100-yard zero resulted in a the arc rising up to meet the line of sight around 60 yards, rode along until about 115 yards, and then gradually descended.
The end result here is that setting a zero stop on an optic and only ever having to correct in one direction makes the whole process a lot simpler.
Why not apply this idea to a 22LR?
I Give You the 22LR 35-Yard Zero
I mentioned at the beginning that I wildly overestimated the adjusted point of impact when I moved from my 25-yard zero to shooting at 50 yards. It turns out that there was a -0.1 mil hold under. That means that the ballistic arc of the bullet continued above the line of sight slightly as it went down range to 50 yards.
When I punched in the numbers at JBM, though, I noticed that the ballistic arc actually peaked at 0.2 mil over the line of sight, and it happened between 30 and 40 yards. So I set the zero for 30 yards and saw that nice smooth “kiss” of the ballistic arc before it began gliding down.
Just to make sure, I also compared this against other loads I use with the Tikka and got the same results, though with a bit of variation. For example, the higher velocity CCI mini mags did it at 35 yards, but both the Lapua Center-X and Eley Target showed the peak around 30, but lasted through 35.
So, from this exercise, I propose that the starting zero for a 22LR precision rifle should be 35 yards.
Exceptions to the 35-Yard Zero
Of course, this isn’t a hard rule for everyone to follow. If you have a specific reason to zero for another distance, such as consistently participating in Appleseed events or other known-distance activities- then of course you should optimize for that.
I also realize that not everyone has ready access to zero their rifles at 35 yards. I’m somewhat lucky in that my local range is indoors and has digital target sliders adjustable in 1-yard increments. On the other hand, you might be limited by your facilities to zero at specific backing distances.
For that, I think a 25-yard zero is still very serviceable. A 0.1 or 0.2 mil difference amounts to a very small amount of difference at these distances. You can see from the chart that 0.1 mils at 30 yards amounts to a tenth of an inch, or about half the diameter of the bullet. That’s probably not enough to worry about.
So there you have it, my proposal that the optimized zero for a 22lr precision rifle is 35 yards. This places the zero at the peak of the ballistic arc so that you will only ever have to dial the turret, or hold over, in one direction- just as we would do it with a full size centerfire rifle.