Home AR-15 Smyth Busters: Is It Important To Level Your Scope?

Smyth Busters: Is It Important To Level Your Scope?

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@CalebSavant recently discovered a spate of videos on the Interwebs that claim it doesn’t matter if your scope is crooked when you mount it on your rifle. Do people actually believe this? After losing a few nights’ sleep over this trend, Caleb has enlisted his fellow Smyth Buster Steve to tackle the matter head on. Normally, a scope is mounted with its center axis aligned with the rifle’s the bore and the crosshairs level relative to the gun itself. Advocates of the “Crooked is OK” school of thought say you should shoulder your rifle and then adjust the crosshairs to make them level based on how you hold the gun.

When you aim, you will have to tilt the rifle to get the crosshairs level with the horizon. As a result, the rifle will be canted, and due to “mechanical offset,” the scope will not be aligned directly over the bore. The point-of-aim and the bore centerline are not parallel. They actually cross each other at some point and then diverge. The scope will be accurate at that point where those invisible lines intersect. But at other ranges, it is not. You can use the scope’s windage and elevation adjustments to compensate for some of this, but no scope has adjustment knobs for DIAGONAL adjustment!

Example: Your rifle has a properly aligned scope zeroed at 100 yards. If you want to hit a target 300 yards away, you just have to aim higher. With the Crooked Method, you have to aim higher AND off to the left or the right, depending on which way you’re canting the gun, to compensate for an imaginary “windage.”

The effects of the Crooked Method get worse the farther away the target is. The longer the range, the more the bore and line-of-sight diverge, and your target groups will open way up. If you’re shooting an AR-15, it’s even worse. The higher mechanical offset of the typical AR-15 scope mount means a crooked scope will be even more dramatically inaccurate at long range! If you’re shooting rapid fire at close targets, a canted scope probably won’t make a noticeable difference in your rifle’s accuracy.

So this myth is thoroughly BUSTED. Don’t let the way you hold your rifle determine how you mount your optic. Mount the optic correctly, and teach yourself how to hold the rifle correctly! There’s a reason why folks who shoot at small targets at long-ranges have their scopes perfectly leveled out, often with the aid of a bubble level.

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30 COMMENTS

  1. On a side note, when shooting with an offset red dot or offset irons, its important to keep the bore of the rifle as close to vertically under the optic as possible when tilting or you will notice that your accuracy will suffer for the same reason.

  2. I wonder how off you would be if not level. Let’s say at 100 you’re bang dead on center. What about 200, then 300. Are we talking inches or maybe not even hitting the paper target? Thanks guys

  3. I’ve shot accurately with a canted scope for years under 300yards. I’m calling bull ****.

    As long as the scope is level while shooting on a zero moa rail and zero moa mount your fine.

    Busted? my **

  4. I also started searching about leveling a few weeks ago and the number of people who said just level your scope to the earth is astounding. They are soo confident in what they are saying in videos and in the comments.

  5. When I used to mount scopes for the public. I first had the customer shoulder the rifle, to find the eye relief, and then leveled the scope to the rifle. I never had a complaint, after they had been at the range fine tuning the optic. One of the goofiest things I have heard in a while. I thought it was some kind of click bait.

  6. I've recently enjoyed long(er) range shooting. I spent a LOT of time leveling the scope to the rifle and have put a bubble level on the scope itself to ensure when I set up a shot, the rifle is now level to the horizon. My first range trip took a 6 foot construction level and set a level line at the 100yd target as an additional reference when sighting in. NONE of this makes me a better shooter but mis-aligning the scope can certainly make me a worse shooter for the reasons you described! (and if I were serious about tighter groups, I'd have to kick my coffee habit)

    Reloading 6.5 PRC for long range shooting is a relaxing hobby compared to my .223, 45 ACP and 9mm "plinking."

  7. I don't know how many times, back in the day, that I had to adjust for this because the crosshairs were not level to the bore. Would drive me nuts until it was right while have shooting buddies tell me it didn't matter. At that time, many moons ago, I didn't have the proper tools to do it right the first time.

  8. basically i just bolt the mounts on figuring the plate will keep my scope rings straight and then eyeball my crosshairs. so far good shape. (maybe i'm lucky) but i hit quarters at 100 yards,

  9. I think it's more of the set it and forget it type people. The type of people who are never really going to shoot past a hundred yards so it doesn't really matter if it's crooked or not. They've zeroed it the way it is and as long as you ain't reaching out I guess it's fine if you have a x instead of a cross in your scope.

  10. I don't think the explanation is quite correct here. Rotating the gun and scope together does nothing to alter the effect of bore-scope offset. The only thing it does is to cross-couple bullet drop compensation with windage because gravity doesn't rotate with the gun. If you manually "hold over" for bullet drop compensation, it will make no difference if your scope is level. If you use a bullet drop compensating reticle, THEN it matters because the vertical axis of the reticle is no longer aligned with gravity. For small angle error, this doesn't make much difference in bullet drop BUT it does introduce a false windage. Likewise, if you adjust the vertical turret to account for bullet drop, having the scope canted will cause this adjustment to produce not only a vertical effect but also a horizontal one which is unintended and will have to be compensated by adjusting the horizontal turret.

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