How to Zero a Scope and Rifle for Long Range Shooting

Tom Mchale gets new Ruger Precision Rifle which means it is time for a short class on how to zero a scope and new rifle for long range shooting.

USA –-(Ammoland.com)- If you’re going to shoot long range, you need to make sure your zero is perfect. Small errors at 100 yards become big ones at 1,000 yards, so if your zero is off by just ½-inch at the 100-yard mark, you’re talking five full inches down range.

We’re going to take a close look at the Ruger Precision Rifle in this long range shooting series of articles, so today we’ll take it to the range for its first outing to get a proper zero. There are lots of ways on how to zero a scope and rifle; this is just the method I prefer. It’ll take more than a couple of shots, but you’ll be confident you’re dead on when you stretch out the distance of your shots.

Mounting the Scope

While we won’t go through the process of mounting a scope here, it’s important to mention one important part of the process—ensuring that your scope is level with your rifle. The vertical crosshair must be perfectly aligned with the vertical centerline of your firearm.

At closer ranges, a less than vertical crosshair won’t matter all that much. However, at longer ranges, a slight misalignment will cause a lateral miss. For example, a single degree of scope cant error can shift your point of impact by five inches at 1,000 yards.

You can check the level of your crosshairs by making sure your rifle is perfectly level and then lining up the vertical crosshair with an object that you know is dead on vertical. Or you can use a tool like the Scope Setter.

Methodical Zeroing vs. Quick and Dirty Solutions

If you’re going to do most of your shooting at less than a couple hundred yards, or perhaps you only care about shorter-range minute of beast hunting accuracy, then quick and dirty methods like the “one-shot zero” and similar methods are fine.

However, tiny errors at 100 or 200 yards become big ones at 1,000 yards, so it’s important to use a more methodical process. Don’t rely on single-shot indicators to determine your zero status. I like to use three-shot groups at each step along the way, except for the initial “get on paper” shot at 25 yards. Using three shot groups allows you to find a decent average impact point given the mechanical variability in your scope, rifle, and ammunition combination. It also helps factor out shooter error. If three shots land in the same area, you can be fairly confident that both you and your equipment agree.

Use the Math when learning How to Zero a Scope for Long Range Shooting

87% of people learning how to zero scopes at the range use trial and error to zero their optics. You’ve seen it. Fire a shot. Look at the target. Spin the turrets one way. Fire again. Spin them the other way. 25 shots later, they’re still chasing the perfect settings.

Fortunately, all of that trial and error is completely avoidable because scope turrets give you all the information you need to make an accurate adjustment on the first try. Most scopes have turrets marked with something like “1 Click = ¼-inch.” Sometimes you might see a marking like “1/4 MOA.”

Here’s what it means. When shooting at 100 yards, each click will move the bullet impact ¼-inch in the direction indicated. Scope measurements like minutes of angle (MOA) and mils (milliradians) are proportional, so if you’re shooting at half the distance, each click will move the point of impact half as much. At 50 yards, that click will move the point of impact by one-half of one-quarter of an inch, or 1/8^th of an inch. At 25 yards, it would be one-fourth of one-quarter of an inch or 1/16^th of an inch. It works the other way too. If you’re shooting at 200 yards, just double the adjustment impact. One click will move the bullet hole two times a quarter of an inch, or ½-inch. Make sense?

Some scope turrets are marked in milliradians, most commonly “1 click – .1 mils.” A “mil” represents 3.6 inches at 100 yards, so .1 mils is .36 (about 1/3) of an inch at that distance. At 50 yards, it’s ½ times .36 inches and so on.

So, when adjusting, you can quickly determine how many clicks are required to get your rifle, in this case the Ruger Precision Rifle on target by looking at how many inches “off” you are. Hold this thought for a hot second and we’ll come back to it as we continue the process below.

Get on Paper at 25 Yards

After mounting a new scope, you really have no idea where the first shot will go. Rather than putting a target far down range and hoping for the best, move your first target up close to 25 yards. You will almost certainly hit the paper somewhere before you make any scope adjustments.

Using the math described previously, you can make some rough adjustments to get close to the bullseye at this close range. Let’s walk through the process with a brand-new Ruger Precision Rifle chambered in 6.5mm Creedmoor.

Heads up—one of you will own this rifle when it’s given away later at the end of this long-range shooting article series, so keep an eye out on this monthly newsletter!

I mounted a Burris Veracity 4-20×50 scope I had handy on the rifle for the first range outing. This optic has target turrets that adjust in ¼ MOA increments per click, so when shooting at 100 yards, each click moves the point of impact ¼-inch. I fired my first shot at the target from 25 yards to get on paper and the bullet was dead center laterally but almost exactly four inches above the bullseye. Hey! Easy math! To move impact down four inches at 25 yards, I calculated 64 clicks “down” per the direction indicator on the turret. Since each click moves the impact ¼ inch at 100 yards, then that would be 16 clicks—if we were shooting at 100 yards. However, since we’re shooting at 25 yards or one-quarter of the distance, each click has 1/4^th the amount of movement at 25, so we have to multiply our clicks by four. I counted off 64 clicks “down” and fired two more shots at the 25-target. Those impacts were right on the bullseye and went into the same hole. Yay Ruger Precision Rifle!

100 Yard Confirmation

Now that I was safely on paper and pretty darn close, I moved the target out to 100 yards and fired a three-shot group. As a quick side note, check the photo on that. All three bullets went into the same hole about 1½ inches low and 1/2-inch left. Three shots don’t make an accuracy test, but I was impressed. Acording to my Lyman Dial Caliper that group measured 0.076 inches. Yes, less than 1/10^th of an inch. Anyway, doing the math again, I adjusted 6 clicks “up” and 3 clicks “right” to compensate, then fired another three-shot group. That group landed dead center in the bullseye and measured an astounding 0.046 inches.

Seeing how closely the three shot groups landed, I fired a quick five-shot group and measured a 0.296-inch center-to-center pattern. I’m really looking forward to evaluating this rifle—it’s a tack driver.

I zeroed this scope and rifle at 100 yards for convenience, not because 100 yards is the best all-around solution. Depending on caliber, optics, and intended use, it may make sense to zero your rifle at 50, 100, 200, or even 300, but that’s a topic for another day.

I didn’t include a final step, long-range confirmation, in this how to zero a scope article, because that’s a separate topic. Initially, we wanted to ensure that the rifle and scope were correctly aligned and you can do that at any reasonable short-range distance like 50, 100, or 200 yards. Before launching long-range shots that count, you’ll need to complete a second verification process to figure out which specific scope adjustments are required for different distances down range. That’s not really a scope “zeroing” issue as much as one of calibrating scope adjustments and bullet velocity, so we’ll cover it later in the series. Stay tuned!

About Tom McHale

Tom McHale is the author of the Practical Guides book series that guides new and experienced shooters alike in a fun, approachable, and practical way. His books are available in print and eBook format on Amazon. You can also find him on Facebook, Twitter, Instagram and Pinterest.