How To Sight In A Rifle Scope Without A Boresighter

Here’s the basic summary: if you’re shooting a semi-auto, your best bet is to make sure your rifle scope is properly attached, then take a shot (or five) at a close distance like 25 yards before the bullet has a chance to deviate so far that it’s off the paper target. Once you’re sighted in at 25 yards, you should be good to sight in at whatever distance you’re looking to zero at.

For a bolt action, you can do the same thing, but you can also simply remove the bolt and look through the bore with one eye and the rifle scope with the other and get them to match up. This process, properly done, should get you at least hitting the target. The windage and elevation dials on the scope will take you from the first point of impact on the target to where you want your shot to land.

If you are looking for more detail on how to sight in a scope and make adjustments on your gun without using too much ammo at the range, then keep on reading.

Sighting In A Rifle Scope Without A Boresighter

Details:

sighting in a rifle scope

The whole idea behind putting a rifle scope on your rifle is to make it easier for you to see where the bullet is going to go when you pull the trigger. The problem is that no matter how perfectly you mounted your scope (unless the Freedom Gods smiled upon you), the bullet and barrel won’t match up perfectly with the crosshairs when the scope is first attached.

You’ll need to adjust it to match if you want to hit the target when you fire your ammo at the range. Your barrel is straight, so all you need to do is get things sighted without a boresight.

The adjustments may not need to be big, you just need to get the scope to match the muzzle of the gun each time you fire. If the scope moves when you shoot, you’ll need to either tighten the mounting or return it. Your line of sight depends on the shooters position, the sights you’re using for shooting, and the distances you’re aiming.

An important thing to remember here is that the bullet’s trajectory is not being adjusted - the reticle moves on the rifle scope to match where the bullet is impacting. Also, remember that the rounds don’t travel in a straight line; they travel in an arc. The bullet impact will be different at different distances in relation to the scope because the view through the scope is traveling straight.

Purpose of Boresighting

how to sight in a rifle scope without a boresighter

Often, when you first mount a rifle scope it is so far off that your shots won’t even be “on paper” (meaning on target), which makes it difficult and aggravating to try to adjust your scope when you don’t even have a clear sense of where the shot placement is currently.

The nice thing with this is that if you don’t have a boresight, all you have to do is find a way to get the rounds to hit paper on the target in order to start making adjustments.

Bolt Action Rifle

how to bore sight a rifle

Bolt actions are fairly straightforward to do this without a boresighter. In fact, many an experienced shooter may not bother to purchase a boresighter if they aren’t in the habit of buying new scopes very often. Instead, you can just remove the bolt and look through the bore. In case it’s not obvious, make sure to do this with an unloaded gun.

You then just compare what you see through the end of the bore to what you see on the sight picture and adjust the crosshairs to match. I’ve seen this done with both eyes at the same time like using binoculars, but you can also just use one eye and move back and forth as long as your rifle is being held perfectly steady.

Once you’ve done that process, you should be hitting paper on the target, and if you’re not hitting at 100 yards, you can always work at a closer distance first.

Semi-Auto

sighting in a scope

Unfortunately, removing the action and staring down the bore of a semi-auto isn’t as practical with a semi-auto, so your best bet here is to just get the target close enough that you’re on paper target without adjusting the sights. Usually 25 yards is close enough for this. If it’s not, you may want to evaluate whether the scope was properly mounted or whether you got a lemon.

Since the scope is basically pointing in the same direction when attached, the scope really shouldn’t be too far off, but I’ve stopped being surprised at how bad a scope can be when first mounted. A larger target will be easier to use on than a smaller target. If your shot is 10 inches off, for example, then your shot may not be on paper with a small target.

The Process Of Sighting In

how to sight in a scope

Zeroing in is fairly straightforward and is a simple process. No matter what kind of scope you bought (even a scope without bells and whistles), it should have at least two dials on it: one for windage and one for elevation. The windage dial will move the sight picture left and right, while the elevation dial will adjust the sight picture up and down.

These two dials are how you move the reticle to match up with where the rounds are landing.

When you’re shooting, make sure to always position the sight picture of the scope over the center of your target. Your goal is to ascertain how far the bullets are deviating from where the reticle says they should be.

I favor taking three rounds between adjustments. I know some who are confident enough in their consistency to adjust between each shot on the target, and some who prefer to take five shots before they make adjustments. Regardless, your process is as follows:

1. Pick the distance and point you’ll be zeroing in and shooting at

2. Take aim and shoot however many shots you need to correctly determine the point of impact

  • There will always be movement, so I recommend taking multiple shots

3. Use the elevation and windage dials to move the reticle to the center of where the bullets are hitting

  • If rounds are landing to the right, move the sight picture to the right, if up, then move up, etc.
  • A good method of adjustment here is to go the target and measure the distance left-right and up-down. This is a way to correctly calculate how much you need to move the scope to have your aim be right.

4. Take another set of shots and repeat as necessary, using progressively more fine adjustments.
It’s nice to do this at a shooting range long before you take your rifles hunting. The process to get the crosshairs in the center requires adjustments based on each shot, but if you fire a few shots at the range you want to shoot at, then you won’t overuse ammunition to get the accuracy you need for hunting.

Final Thoughts

In my experience, the biggest problem that new shooters have is thinking that sighting in a rifle is more complicated than it actually is. They’re usually doing it right and just don’t believe that getting their sight on target without a boresight is that easy.

My last tip for success would be to use a mounting system if possible (like the lead sled) to mount the rifle up on a solid rest so that the scope holds steady. 

If you’re relying on your own skill in holding your scope and rifle steady while sighting in, you’ll probably eventually get it there, but it will be a lot more frustrating and time-consuming. Remember, once you’re on target, it gets a lot easier to move the crosshairs of the scope to where each shot is impacting.

Sighting in other types of guns is the same process, though it’s unlikely you’ll be able to see through the center of the bore to measure how accurate the scope is before firing. If you make too big of an adjustment, you’ll just have to adjust back between rounds. You can also check out this helpful  YouTube video.

If you’ve got more tips for beginners trying to make this process work, please leave them in the comments.

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