This is probably one of the most asked questions by new rifle shooters. It’s usually asked a few weeks after their “what scope should I get?” post, which was probably an equally debated topic of discussion depending on the day of the week and if the At***n dealers are online.
It is one of the questions that gets asked over and over again because each cartridge, rifle, shooter and situation dictates the proper answer.
What works for a short range hunter will not work for a long range hunter, or a Palma shooter. And what works for a Palma shooter will not work for a PRS shooter, or a tactical team, and so on. Each discipline has reasons for why their shooters sight in at a specific distance, and even within that group there will be outliers.
Universal Basics behind Zeroing a Rifle
First let’s talk about some of the universal basics behind zeroing a rifle.
Apart from the specifics of application, and cartridge there are some rules that should be used for every rifle.
First, be able to call your shots accurately. It is rare for any shooter, yes, even good ones, to break every shot dead center of their intended point of aim. There are always small variations in position, cheek weld, heart rate, breathing, and trigger control. Be as honest and as precise with your calls as possible, the only person you are fooling is yourself. You can make calls based off of parts of the target or using the clock method.
For example, on a bullseye style target I could say ½” outside the 10 ring at 3 o’clock. This gives me a very precise location of where the shot should go, if it does, then I do not need to adjust my zero.
Next, don’t zero your rifle at 25 yards.
You will hear lots of tall tales about shooters one hole groups when they zeroed their rifle to only find out the group was shot at an embarrassingly close distance.
Even if your intended application for a rifle is primarily close range you always want to confirm at a long enough distance to actually see if the zero is correct. To actually see if your zero is off at 25 yards it would have to be off by around 4 minutes of angle (MOA). Which is a lot. This equates to 4” of error at 100 yards.
So on the rare occasion you’ll need to use your close range rifle for further targets you now have a fairly large error already induced to your shot process.
Additionally, It is difficult to make precise calls if you are too close to the target.
That being said, it is also ill advised to zero too far away.
This can cause the wind to become a large source of drift in your group. This will make it difficult to determine the actual lateral position of your group. You want to find a happy medium between the two. Use as stable of a position as possible, typically prone off of a bipod or bag is best, and if it is windy that day, don’t forget to calculate that into your process.
Wind will always have an effect on the trajectory of the round, regardless of distance, the question is “was that gust, or let off, enough to noticeably shift the impact?”
Lastly, don’t do anything that could have a negative effect on the trajectory.
This one is a little bit vague, but it is very important. If your rifle is free floated it’s very easy, don’t have anything touching the barrel while trying to sight it. The big one that you might run into is the MagnetoSpeed chronograph. It attaches to the end of the barrel for its velocity readings. While you will be able to get a rough zero with it attached, always confirm after you have removed the chronograph.
Also, if you attach or remove a muzzle brake or suppressor, this will affect your point of impact. If your rifle is not free floated it is a little more difficult. You don’t want anything putting pressure on the barrel or the rail that is contacting the barrel when zeroing. This causes a phenomenon called barrel flex.
Essentially what happens is your optic that is affixed to the receiver will remain stationary and your barrel will move slightly away from any pressure that is being applied. When the pressure is removed it will settle back in its natural position. To see some cool pictures on this effect in action look up the “barrel flex test” on the Marine Corps Shooting Team Facebook Page. The post demonstrates the effects of different positions, barricades and weights have on the point of aim versus the point of impact.
Rifle Application
Now that we have some of the basics out of the way, let’s look at the application.
The application that the rifle is going to be used for will dictate the best distance to sight in at. A hunter on the east coast that mainly does woods hunting may not have the ability to shoot long distance, but every now and then may have a mid range shot out to 300 yards in a field.
A 200 yard zero could be very beneficial depending on the caliber. This would allow for only a few inches of spread between points of impact at 50, 100, 200, and 300. All of which should be within or very close to the vital zone of large game. Additionally, when a hold-over is needed for longer distances it is easy to eyeball as you are only estimating if it is over 200 yards. But, if that same hunter is going out west and could be engaging from 100 yards out to 800 yards, or more, the plan changes.
Now a 100 yard zero would be better and the hunter should use a ballistic calculator to confirm their hold for the actual distance of each shot. This allows for them to hold center if they come across an animal at close range. If they have distance, then they also have time, which allows them the advantage of refined holds and wind calls.
For competition shooters it varies by discipline.
Bullseye shooters may have a base zero at their shortest shot and then they will use confirmed data for each position and yard line after that.
When I shot high power I would zero at 200 (Our shortest distance) for my sitting position. This was due to the fact that sitting at that distance was worth half of my possible points for that yard line and all shots were fired before scoring was done. My standing position at the yard line was scored after each individual shot, so if there was a small adjustment needed it wouldn’t cost me very much in my score. There was no reason to zero in the prone at that distance since that position was not used until later at a further yard line.
For NRL22 I zero my rifle at 50 yards. This is because the wind has a greatly reduced effect on the impact of the round at this distance compared to 100 yards, yet it is still far enough that I can see a 1 MOA error in my zero. With my rifle it also uses the same data at 25 yards and 50 adding an additional benefit to the zero. At centerfire NRL/PRS matches, you will almost always see a 100 yard zero. For most standard rifle cartridges this is that perfect medium allowing for minimal drift while giving the shooter fine adjustments.
On another hand, some extreme long range shooters utilize 300 or 500 yard zeros because the closest shot they will take is 1000 yards. They are also utilizing large bore wildcat cartridges that have much higher ballistic coefficients and shed off the wind much better than their short action counterparts.
Tactical shooters probably have the largest possible engagement spread that has to be considered. This is why, for 5.56 rifles, the 36 yard zero is sometimes utilized if they are using a Rifle Combat Optic (RCO) with a bullet drop compensator (BDC) reticle. They zero with their 300 yard reticle mark on the 36 yard target. This is because with standard issue ammo their 36 yard and 300 yard zeros match. Once that zero is achieved they confirm at 100 yards utilizing their 100 yard aiming point. Keep in mind this is for an RCO with a BDC reticle.
If you have a MRAD type reticle a 100 yard zero is a great option as everything closer than that has a less than 2” offset from zero, which is well within the needed parameters of almost any situation. Zero’s past 100 yards are not ideal for these rifles since wind starts to play are larger factor in the point of impact versus the point of aim.
Regardless of application, the type of cartridge, projectile weight and velocity have a part to play in what could be possible zero distances. A 6.5 Creedmoor is able to zero further than a .223 without the effects of wind, even if both rifle are being used for the same application. It is imperative for the shooter to know and understand the effect their projectile and velocity play on the possible wind drift of their round, and how that could change where they should zero their rifle.
Unfortunately, as with most of our topics, there isn’t a straight forward, one size fits all, answer to this question. It is up to the shooter to consider their application, cartridge, rifle and ability to determine the best possible distance to sight in their rifle at.