Stop Asking What You Should Zero Your Rifle At
I have been wanting to write this one for quite some time as I constantly see this topic in various places across the internet, hear the question at matches, and get it asked to myself fairly often. I am of the opinion that your thorough understanding of this one specific topic will make you a much better shooter without ever working on technique. Don’t get me wrong, technique and practice are key foundations to growing your shooting skills, but they don’t mean anything if your weapon systems are not set up correctly.
When it comes to shooting competitions, the stages I end up ranking at the top of are often carbine stages with targets ranging from 300-800 yards. There are often fundamentally better shooters in those matches that place behind me in this type of stage, I believe, simply because I know my weapon system and specifically my zeros and holds a little bit better than they do.
When someone asks “What should I zero my rifle at?”, you need to understand that this question is like asking “EXACTLY how fast I should run this first mile?” Certainly anyone in their right mind would not be able to answer that question for you because there is a range of factors that come into play. When you are asking about a rifle zero, you are asking about a specific singular number that all other numbers, in front and behind it will be based off of. The answer to this, just like many other questions in the shooting space will always be “It depends.”
That answer, “It depends”, tends to turn most people off as they begin to either anticipate a long drawn out process to find the real answer or they simply shy away from the journey as they really don’t know where to begin. I am hoping I can make this easy enough that anyone will be able to answer this question for themselves going forward. Make no mistake, you can ask the question, get an answer, and probably do fairly well with whatever you are given. However, you will never be able to shoot, hunt or defend yourself as efficiently as someone who is able to derive these numbers themselves.
I am one that studies and contemplates on a consistent basis, likely much more than most, but acts upon those learnings much less often than others. I like to try to get decisions, purchases, etc right the first time. It’s partly because I am built in such a way that the journey is more important than the destination and the chase is more important than the kill. Due to this personality trait, almost everything I do must answer the first questions, “Why?” or “What?”
The first process to determining your proper zero is determining your use case. The use case is a highly valuable basis for many decisions inside shooting sports and one that you should consider for other things in life like vehicle or clothing purchases. Without a “use case”, you cannot even begin to consider what “best” for you would be. We must first establish the type of activity you will be using your weapon system for in a very specific manner and then we will establish how YOU like to execute that activity. It is not merely enough to define your use case as “hunting”, nor is it enough to specify a specific type of hunting, like deer hunting, without also establishing your terrain and range as well as the way YOU, and you alone, like to execute that particular type of activity.
How YOU execute your activity is just as important as the use case. Some will prefer to never have to worry about holding over in their scope or dialing. Some will prefer to hold over but not dial, some will want to do the opposite and some will want to do both. Some people will prefer to execute their activity at close range whereas others will prefer the engagement be at longer distances. If you haven’t figure this out yet, this is all highly personal and another reason why the main question we are addressing here is absolutely ridiculous if the answer comes from some one else.
I am going to make an assumption that most people reading this will likely have an interest in Run and Gun or other dynamic style shooting competitions so I am going to use an example of how we would establish a zero for this type of event. Here are the bullet point questions we need to ask ourselves.
What type of shooting event is this?
Why type of weapon system do I intend to use?
What is my range of engagement for this activity?
What range is the majority of engagement going to be at?
How can I most efficiently execute my engagements?
Assuming I am running this event, this would be how I would likely answer these questions.
What type of shooting event is this? (Run and Gun)
Why type of weapon system do I intend to use? (5.56 Carbine, 13.7” barrel)
What is my range of engagement for this activity? (10-600 yards)
What range is the majority of engagement going to be at? (75-125 yards)
How can I most efficiently execute all my engagements? (Hold under/over)
In this type of scenario, where quick engagement is the key to success and the targets are typically larger, holding under/over will likely be the most efficient. However, if this event had engagement distances of 10-300 yards, I would likely change my zero completely to a MPBR zero (more on this later) AND NOT HOLD AT ALL. If the targets were much smaller and the majority engagement range was more spread out, I would likely choose to dial my holds and this also might (not always) change what I decide to zero the rifle at. Once I have these answers, MY personal answers, then we can begin the process of figuring out where we need to zero the rifle.
Before we go any further on the process of how to determine this number, we first need to address how do we actually zero the rifle at any distance. I want to make it clear, I absolutely HATE zeroing rifles. I hate it because everything must be as exact as possible and I am very particular to ensure that it is. I believe that this is extremely important to your overall success. You can get everything else right, and your sight height calculation be off, and the only number you will have that matches up to your DOPE chart will be the actual zero itself. Nothing in front, and nothing behind that number will be correct. Because I am very particular in this process, it takes time and I usually pull out a few hairs in the process.
Step number 1 is making sure our optic is mounted properly. I am not going to go into detail on this as that could be an entire article in and of itself, but make sure whatever optic you are using is mounted and aligned properly on the rifle and snugged down in the appropriate manner using torque wrenches. Most common mistake by far is over torquing. For scope leveling, I have tried about every possible contraption out there and in my mind nothing beats a plumb line at 100 yards. Your mileage may vary.
Step number 2 is making sure we have an EXACT height over bore measurement. You want to measure from the center of the optic or optical tube/window to the center of the barrel. This measurement should be as precise as possible and I recommend something like a micrometer, not a ruler.
Step number 3 is making sure we have chronograph data for the load/round/cartridge/ammo, whatever you want to call it, shot from our specific gun. When I say specific gun…I mean by serial number. Not by make, or model. Not the numbers your buddy’s same type of gun shot with the same ammo. Your ammo. Your gun. Period. Ideally, I like to see three 10 shot strings (cooling after each string) from two different outside ambient temps that are fairly far apart. If you can get in 3 separate 10 round strings at 45 degrees and then 3 separate strings at 85 degrees that is plenty. I typically will toss the highest and lowest of each string and average the middle 8. We do the two separate temperatures so that we can have a correction factor for temperature sensitivity. Most apps, will provide one for the particular cartridge, but its better to have the date. Even if you only shoot one 10 round string, I assure you that is still far better than taking data from a buddy or off of a box of ammo.
Once we have our chrono data, our bullet data (grain weight, ballistic coefficient) and our sight height, we also need to know the twist rate of our barrel. We will take all of this data and plug it into a known reliable ballistic app such as Applied Ballistics, Strelok, or the Hornady 4DOF app or similar. In the below example on my main run and gun rifle “Joseph” you can see the following parameters:
Scope: 2.46 sight height
Ammo: 73g Hornady ELD-M (0.2 G7 BC)
Speed: 2486 fps @ 80 degrees
Twist Rate: 1:7 Right Hand
In this particular example, where it says “Scope: 50” it means I have zeroed this rifle at 50 yards.
Once I have this info in the system, I will set it up to spit out my data. If I were doing this to get true data, I would also input my environmental factors when zeroing, when chronoing, and then adjust the environmental factors in real time prior to making the shot. The better your data is, the more accurate you will be. When I shoot a Run and Gun and I know my launch time, I don’t calculate my data until I have checked what the weather will be when I am out on the course…I want to be as accurate as possible with all inputs.
Using the above information, I calculate the data and we get this:
When you look at this data, you want to really read what it is telling YOU. Its clear that with this 50 yard zero, for the way I like to shoot, that I don’t have to worry about adjusting much of anything from 25 to 225 or 250 yards. I am 0.9” high at 100y, which is negligible for what we are using the rifle for, 4.6” low at 225 yards, again, negligible, and 7.2” low at 250 yards. All of these distances I know in my head I can hold slightly low or slightly high to get my hits without much thinking. Once we get to 300 yards, we are 14” low. Now that may seem like a lot, but a full size IPSC is 30” tall, so here is what our hold looks like at 300 yards:
That’s not so bad right? So how we would shoot a stage with a target array from 100 to 300 yards is pretty simple. We would hold dead on for almost everything out to 225, and cheat a bit high at 250 and hold on the target’s head at 300. Easy, peesy. There is no reason to make this complicated. But what would happen if I had zeroed my rifle at 100 yards instead?
Now we can see, that with my sight height, my bullet speed and all my other data, that a 100 yard zero changes things a little bit. I am now 1.3” low at 150, 9.4” low at 250 and 16.8” low at 300.
And if we change to the new cool guy 36 yard zero?
We are now 2.6” HIGH in the middle at 125 yards, only 3.4” low at 250y and only 9.5 low at 300y. If I was shooting matches only out to 300 yards, and expected no small targets in the mid ranges, this may be a better choice. For me, I don’t want to be 2.6” off at 125 yards. That’s over 2 MOA, and if I am presented with a small target at that reasonable distance, I want to hit it. Again, your mileage may vary, because how you zero your rifle and you choose to engage is very personal.
One thing I want to point out, is my scope height of 2.46 over bore, is quite low. I use a 1.25” high mount to achieve this, whereas most LPVO mounts are 1.5 to 1.54, and now days the popular tall mounts are 1.90 to 2.1 high. This will greatly affect how your individual DOPE charts look. If you are running a really tall mount, your offsets at the middle ranges will be much larger, and it may not be advantageous for you to have a short range zero. This is why it is important for you to do the due diligence with your particular set-up.
If I was going hunting and I knew the spot where I hunted had a maximum distance of 250 yards, and the game I was shooting was whitetail deer, the 36 yard zero would prove about perfect on my particular setup. We would be no more than 3.4” high or low from 25 to 250 yards and the deer’s vitals are about 8” in diameter. I could simply zero at 36 yards, go hunting and hold dead on. If my cartridge was faster, I might could stretch that 3.4” window to 300 or 350 yards. Zeroing so that you can hold in a certain window without worry, is known as Maximum point-blank range or MPBR: The distance (in yards) a projectile (bullet) can travel without rising or falling more than a predetermined measurement above or below the point of aim.
For my hunting applications, I play around with the zero’s in my ballistic app until I find that sweet spot. I write that yardage range down, along with the maximum high/low and I don’t worry about anything inside that distance. If I need to take a shot outside of that yardage range, I would simply dial or hold the proper elevation.
I even use my ballistic app for my pistol mounted red dots. Coincidentally, the zero I like on my pistols is also 50 yards. I would rather be slightly high or low with any weapon system at a close range, where I can see my hits and be able to adjust than I would having to hold over/under at distance. If I know my weapon is 3” high at 7 yards, I can adjust very quickly when I see the first round on paper/steel. If I have to hold 3” high at 50 yards…well that’s a tougher calculation for the brain to make and I also may or may not be able to see my errors. Again, your mileage may vary.
My guns have a wide range of zeros depending upon the application of that gun. I want the zero to be as functionally efficient as the rest of the gun, and ultimately I want the zero to take the pressure off of me. Regardless of whether it’s hunting, competition or self-defense, I need to be able to think clearly, make adjustments in real time and keep things simple inside my head. All three of those scenarios create a fog of war, and if you know your weapon system inside out, along with its capabilities, then the rest of your energy can be focused on cracking that perfect shot.
To chat about this blog entry and much more, join us on Discord:
https://www.twobluescrews.com/join-us-on-discord
