Getting your shots to hit exactly where you aim starts with a proper setup. Learning how to calibrate rifle scope is the essential skill that makes that happen. It might seem technical, but with patience and the right process, any shooter can do it. This guide will walk you through the simple, step-by-step method to zero your scope, ensuring your rifle performs as it should.
A well-calibrated scope builds confidence and improves your accuracy, whether you’re at the range or in the field. We’ll cover the tools you need, the preparation steps, and the actual shooting process to get you dialed in.
How to Calibrate Rifle Scope
Before you fire a single shot, proper preparation is key. Rushing this stage is a common mistake that leads to frustration and wasted ammunition. Let’s get your rifle and gear ready.
First, ensure your rifle is unloaded and the action is open. Safety is always the number one priority. Mount your scope securely using a proper torque wrench if possible. Loose rings are a major cause of shifting zero. The scope should be level and at the correct eye relief distance for you—when you shoulder the rifle naturally, you should see a full, clear picture without any dark edges.
Next, gather your essential tools:
* A solid shooting rest or sandbags for maximum stability.
* Your target, preferably with a clear bullseye or grid.
* Ammunition from the same lot for consistency.
* A screwdriver or the specific tool for your scope’s adjustment caps.
* Eye and ear protection, of course.
* A spotting scope or binoculars to see your hits clearly.
Choose the right zero distance. For many rifles, 100 yards is a standard starting point. For rimfire or certain hunting setups, 50 or 25 yards may be more appropriate. Check your scope’s manual for its specific adjustment values (usually in Minutes of Angle or MOA).
Preparing for the Initial Shots
Now it’s time to get a rough zero, often called “boresighting.” This saves ammo and gets you on paper. You can use a laser boresighter or use a simple visual method.
For the visual method, secure your rifle solidly in its rest. Remove the bolt if your rifle allows it. Look directly down the barrel (the bore) and center the target’s bullseye in the barrel. Without moving the rifle, look through the scope. The crosshairs will likely be pointing somewhere else. Carefully adjust the windage (left/right) and elevation (up/down) knobs until the crosshairs are centered on the same bullseye you see through the barrel. This gets you close.
The Firing and Adjustment Process
Move to your live-fire range. Set up your target at your chosen zero distance. Take your time to get comfortable and stable behind the rifle. Fire a three-shot group. Don’t adjust between shots; the goal is to see a tight cluster, not a perfect single hole.
After the group, let the barrel cool. Use your spotting scope to locate your group. Now, here’s where you actually calibrate. Let’s say your group is 4 inches low and 2 inches to the left of the bullseye. You need to move the point of impact up and to the right.
Remember the simple rule: “Follow the hits.” To move your point of impact up, turn the elevation knob in the direction marked “UP.” To move it right, turn the windage knob toward “R.” Most scopes have ¼ MOA clicks, meaning one click moves the impact ¼ inch at 100 yards. So, to move 4 inches up at 100 yards, you’d need 16 clicks (4 ÷ 0.25 = 16).
Fire another three-shot group after making the adjustments. See where the new group lands. Make finer adjustments now, maybe just a few clicks at a time. Repeat this process—shoot a group, adjust, let cool—until your point of impact matches your point of aim.
Finalizing and Confirming Your Zero
Once you’re centered at your chosen distance, it’s time to confirm. Fire a final three-to-five-shot group. This group should be nicely centered around the bullseye. The size of this group shows your rifle and ammunition’s inherent accuracy.
Record your settings. Some shooters mark the zero on their adjustment caps or note the number of clicks from a baseline in a log book. This is helpful if you ever need to re-zero or make adjustments for different distances.
Consider a “box test” to verify your scope’s tracking. Fire at the bullseye, then dial a set number of MOA up, right, down, and left, returning to zero. Your final shot should be back in the original group. If it’s not, there might be an issue with the scope’s mechanics.
Troubleshooting Common Problems
If you’re having trouble, check these common issues. If your groups are consistently inconsistent (called “flyers”), the problem is likely your shooting fundamentals or the ammo, not the scope. Focus on steady trigger pull and follow-through.
If adjustments don’t seem to move the point of impact correctly, double-check that you are turning the knobs the correct direction. Also, ensure the rifle is truly stable for every shot; small changes in your position can create big changes on target.
Persistent horizontal stringing might indicate a canting rifle. Make sure the scope’s reticle is perfectly level with the rifle. And always, always ensure all mounting screws are properly torqued from the base to the rings.
Maintaining Your Calibration
A zero can shift due to hard impacts, loose screws, or even significant temperature changes. It’s a good habit to check your zero periodically, especially before an important hunting trip or competition. Store your rifle properly and avoid banging the scope against doorways or hard surfaces. With good care, your calibration will hold steady for a long time.
Frequently Asked Questions
How often should I re-zero my rifle scope?
You should check your zero at the start of a new shooting season or before a major trip. Also check it if your rifle suffers a hard bump or fall. Ammunition changes always require a fresh zero.
What’s the difference between mechanical zero and true zero?
Mechanical zero is when the adjustment knobs are centered in their internal range. True zero is the specific setting where your bullets hit your aiming point at a given distance. You always work to find your true zero.
Can I calibrate a scope without shooting?
Laser boresighters can get you very close, but you must confirm with live fire. Atmospheric conditions, rifle harmonics, and your specific hold can only be accounted for by actually shooting the rifle.
Why do my adjustments sometimes seem backwards?
This is usually user error. Remember the rule: “Follow the hits.” If your hits are left, you want to move them right. So turn the knob toward the “R” marking. Take your time and think it through logically.
Is a 50-yard zero good for my .223?
A 50-yard zero is common for .223/5.56 rifles, as it often provides a point-blank range where you can aim dead-on out to around 200 yards without holding over. The best zero depends on your cartridge, bullet weight, and intended use.
Calibrating your scope is a fundamental part of rifle ownership. It connects you to your equipment and builds the foundation for accurate shooting. By following these steps methodically, you can trust that when the crosshairs are steady, your shot will find its mark. Grab your gear, head to the range, and put this knowledge into practice.