How to Sight In a Rifle Scope

A rifle that is not zeroed is a rifle you cannot ethically hunt with, and yet sighting in is where more ammunition gets wasted than anywhere else in hunting. The usual failure is not a lack of shooting skill. It is doing the steps in the wrong order, guessing at turret math, and firing a fresh group after every single click. Do it in the right sequence and a hunting rifle is zeroed in about a dozen rounds and fifteen minutes at the bench.

Before anything else: confirm the rifle is unloaded, the magazine is empty and the muzzle is pointed in a safe direction. Every step below assumes you are following the standard rules of firearm safety at all times, and that you are at a range or a safe, legal place to shoot with a proper backstop.

Step 1: mount the scope properly, or none of this works

More “bad scopes” are bad mounts. Use rings matched to your scope’s tube diameter and low enough that the objective bell just clears the barrel. Set eye relief so you see a full, edge-to-edge sight picture while holding the rifle in your normal shooting position, not while craning forward at the bench — the position you shoot from in the field is the one that matters. Level the reticle to the rifle so the vertical crosshair matches the bore axis.

Then torque the ring caps evenly, alternating between screws, to the value the ring maker specifies. Use a torque wrench. “Snug by feel” either crushes the tube or lets the scope creep under recoil, and both look identical to a scope that will not hold zero. A basic inch-pound torque driver costs about as much as two boxes of ammunition and prevents an entire category of problems.

Step 2: bore sight at 25 yards

This is the step that saves the ammunition. On a bolt action, pull the bolt out, rest the rifle solidly in sandbags or a rest so it does not move, and look straight down the bore at a target 25 yards away. Get the bore centered on the target. Now — without moving the rifle — turn the windage and elevation turrets until the crosshair sits on the same point the bore is looking at.

That is it. You are now close enough that your first live round will be on paper. A laser bore sighter does the same job faster and works on rifles you cannot see through, but it is a convenience purchase, not a requirement, and it still needs confirming with live fire.

Step 3: three shots at 25 yards

From a solid rest, fire three careful shots at the target center. You are not trying to zero here; you are confirming that the bore sight worked and getting a rough correction in. Adjust the turrets to bring that group onto the aiming point, then move to 100 yards.

Fire three-shot groups, not single shots. A single shot tells you nothing about where the rifle shoots; it tells you where one round went, which includes your own wobble, the wind and a coincidence. Three shots give you a group center you can actually measure from.

Step 4: the 100-yard group and the math

Set up at 100 yards with the same solid rest and the same ammunition you will hunt with. Different loads print in different places; zeroing with cheap range ammunition and hunting with premium bullets is a common and expensive mistake. Let the barrel cool between shots — a hot thin sporter barrel walks its groups, and you will chase that walk with turret clicks and never catch it.

Fire three rounds at the center. Now measure from the center of that group to your point of aim, in inches, vertically and horizontally. Suppose the group is 3 inches low and 1 inch right.

One MOA is approximately one inch at 100 yards. Most hunting scopes adjust in quarter-MOA clicks, so four clicks moves impact about one inch at 100 yards. Three inches low means twelve clicks of “up.” One inch right means four clicks of “left.” Check your turret cap before you assume this — some scopes use half-MOA or milliradian adjustments, and the cap tells you which.

Adjust once, then fire one confirming three-shot group. If it centers on your aiming point, you are done. Resist the urge to adjust after every shot; that is how a fifteen-minute job becomes a box of ammunition and a rifle that shoots nowhere in particular.

Step 5: write it down, then confirm it later

Record the ammunition brand, bullet weight, the zero distance and the date, and keep it with the rifle. Then confirm the zero again a week before the season opens — three rounds, one group. A rifle that rode a truck all summer, got leaned against a tree, or took a knock in a case does not necessarily still shoot where it did in July. Three rounds is a cheap insurance premium against the one shot that matters.

What zero distance to use

For the vast majority of hunting, zero at 100 yards. With a typical deer cartridge that keeps you within a couple of inches of point of aim from the muzzle out past 200 yards, which covers almost every shot a whitetail hunter takes. A 200-yard zero flattens things out for open country but puts the bullet noticeably high at 100 yards, which is a real problem on a close timber shot at a small vital zone.

If you want to understand what your specific load does past your zero distance, use the manufacturer’s published ballistics rather than a rule of thumb, and then verify it on paper at the ranges you would actually shoot at. Holdover marks in a ballistic reticle are only data once you have confirmed what each one does with your ammunition.

The five mistakes that waste an afternoon

• Skipping the bore sight. It is free and it saves ten rounds.
• Adjusting after every single shot. Groups, not shots.
• Under-torqued or over-torqued rings. The single most common cause of a rifle that will not hold zero.
• Zeroing with different ammunition than you hunt with. Different loads print in different places.
• Shooting a hot barrel. Let it cool; you are chasing heat, not error.

Do those five things right and almost any scope in our budget rifle scope roundup will shoot better than most hunters can hold. Do them wrong and a $600 scope will look like a lemon.