Leveling A Scope, and How To Verify question

Maybe I'm overthinking this, but humor me for a moment if you will.

I've been leveling my scopes on my model 12 actions by using a very sensitive Machinist's Kerosene Level across the turret cap and parallel blocks mounted to the tang of the action. But it recently occurred to me that, although this might get me in the ball park, it is by no means accurate. What really matters in my estimation is the relationship between the scope's reticle and the erector mechanism inside the scope. Are they properly aligned, how to check that alignment and what to do if they're not exactly aligned?

I've read about and tried tall target tests, but unless the rifle, load and shooter are capable of reliably putting a 5 shot group into one hole (I'm not), there is margin for error in that test and results will be somewhat inconclusive.

I have mounted the scope to a solid mount and used a plumb bob at a distance to check erector reliability, and found errors. But is that a proper test? My mount would need to be leveled precisely in two planes ( it wasn't) , but if the scope housing that I'm using as the mounting point is not precisely aligned with the reticle and erector, how good is that? Would not any misalignment induce errors? I suspect that most scope would never pass such a test.

In my book, close is only good enough in horseshoes, hand grenades, and H-bombs, everything else is measured in thousandths of an inch. What do the experts say?

The "bore sight on a plumb-bob line" has done it for me for decades.

Clamp the rifle with it sighted on the line & the vertical cross-hair running down it and then bore sight that the plumb line is centered in the bore.

But then 300 yards is way out there for me so microscopic errors don't matter.


Anything you try on the outside of the scope housing (like milling levels on the scope caps) assumes the reticle is perfectly aligned with the housing. Maybe is, maybe is not.

I think your over thinking this a bit. I purchased a scope lever kit. Fairly inexpensive. One level goes on the turrent and other goes on rifle. I did also purchase a scope level so when I’m out shooting, I know to level before pulling trigger. It was a Burris level. I did level that too when I leveled my scope.
https://www.burrisoptics.com/accesso...ope-tube-level
https://www.amazon.com/Wheler-Engine...JQXR3D7NKWPK6C

Using levels assumes the scope base and rings are perfectly aligned with the bore of the rifle as well as the recticle is level with the body of the scope. Although for most purposes, it is sufficient. I never thought of the plumb bob method, but I will be trying that out soon. Great idea!!

Rosewood

Plumb bob never fails.

Neither does a corner of a multistory house/building some distance away.

Plumb bob is the way to go as already said above. And if you mount a horizontal level to scope tube in correlation to plumb bob and vertical then you will be right on. At least to within tolerances of the erector assembly.

The plumb bob is an interesting idea, never tried it exactly that way. Probably get me to within .1 to .2 moa alignment, but I can't see it doing more. OK for a hunting rifle though. I've placed a plumb bob on a backstop at 100 yds, and tried to do some scope work, but with no way to clamp the stock solidly, I got nowhere.

The Wheler level, level, level is a nice marketing job, but it does less than I'm already doing by using a level across the tang and on the turret cap. Again, no reliable datum points there. Like horseshoes.....

Leveling the stock is probably just a fools errand. No way to know the relationship between the action, the action's scope mount and the stock. A level mounted to the scope tube will help keep from canting the rifle during a shot, but there is no way to know if it's also aligned with the erector. Reticle, yes with the help of a plumb bob, but not the erector.

I've tried a level across the Picatinny rail, but ring attachment is not exactly a close, repeatable fit. And as far as my using the tang as a leveling point, I have no idea if it's parallel to the top of the action where the rail mounts, or if the rail mounting threads are perpendicular to the plane of the tang. In a best case scenario it's likely there are allowable tolerances that stack adversely.

I'm sure someone has figured this all out, and probably sells his/her time dearly to anyone wanting that kind of accuracy, and I'd bet a custom action is the minimum required.

Please keep the ideas coming, you guys are a wealth of information and I appreciate the time you take to think about and respond to my questions. Your advise is always welcome and appreciated.

I use to put a lot of effort into scope mounting but then I thought about why I cared.

The conclusion I came to was, the relationship between the reticle, action and the stock really does not matter. The only thing that is important is that when you are using the reticle for hold overs, or making measurements, that the reticle being held verticle.

Now when I get a new scope, I go to the range with my carpenters level. I draw a cross on the target as perfect as possible. Then at the bench I find the most comfortable shooting position I can and then align the cross hair to the cross I drew on the target. For my target guns I then install a can't level to the scope and adjust it so it shows level when the reticle is aligned with the cross on the target.

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If you use a plumb bob and a level on your scope, so long as the level and crosshairs are ‘matched’ you will be on the money, regardless of action or stock fitment. So long as you maintain ‘level’ while you’re shooting and or making adjustments for elevation or windage. If it was comfortable to shoot the rifle with a 10 degree shouldered angle it wouldn’t matter. The scope to bore alignment remains fixed, and so long as you verify you’re reading level on the optics it will shoot true. Again the level and crosshairs must be in agreement.

Cheers

Thank you for the tip, Stumpy and Rusty. I'm going to try the plumb bob string method. In your experience, what is the best distance away from the muzzle to view the string through the barrel? Do certain colors of string or lighting situations make it easier to center the plumb line while viewing through the bore?

And my many thanks to all other who took the time to respond and share experiences. Your input is always valued and welcome.

Every time I try a level on the action and one on the scope cap the crosshairs look crooked. I just eyeball it.

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Originally Posted by 243LPR

Every time I try a level on the action and one on the scope cap the crosshairs look crooked. I just eyeball it.

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That's those high end scopes Haha.


Texas are you using a 98?

I use a pocket level on the tang, hang a plumb bob on wall and shine a flashlight back through the scope. Crosshairs will be projected on to the plumb bob. Adjust as required.

Set of feeler gauges is another example. Also, the scope is more important to be level with the shooter's fundamental position with the rifle since immaterial cant is just that. Hold the rifle up from a natural position and focus on level vertical and horizontal objects. It is from here you determine a scope that is level with the shooter combined with the ground. A scope lined up with the bore is less important. Thus, you should be able to mount a scope without levels.

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Scope body itself must be level, and the reticle must be in agreement...if the scope is defective with a canted reticle, it's impossible to make accurate corrections.

http://www.accuracy-tech.com/effects...anted-reticle/

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Originally Posted by Robinhood

That's those high end scopes Haha.


Texas are you using a 98?

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I guess not...what's a 98?

I use a weapon mounted level on the same rail the scope is attaching to first level the rifle. I attach my rings and drop my scope in them setting eye relief and level the scope off the top turret. I then verify using a bright flashlight and a dim room to shining the flashlight through the objective while the rifle is level of the rail mounted level. This projects an upside down image of you reticle on the wall which you can verify with a plumb line. This will also tell you if your reticle matches your turret etc.

The next thing to do is a tall target test or take it out and verify dope. If all inputs are correct, ammo consistent, and your dope is not lining up then a tall target test is a must to verify if there is a degree of error in your turret adjustments. If this is verified as good then consider tuning the entered BC or utilize a custom drag curve etc. to get your dope to line up. This is the process I use when setting up a rifle to eliminate all factors and ensure my ballistic app will track through different weather conditions etc. inside 600yds it's not to big a deal, but beyond that it starts to show depending on the target size and wind conditions you're dealing with.

I see the logical progression of your steps in setting up the scope, Lonewolf. And i've used many of the same steps however, I still get groups moving off axis as I crank in elevation. So my question is this: After going through all your set up steps and tall target confirmation, what do you do if, for example you find that cranking in 25 moa of elevation also produces 3.5 minutes of left windage? Do you cant the scope clockwise to compensate? Send it back for reticle alignment? Which variable in the mounting and confirmation process do you focus on to find and fix the problem?

If I mount the scope to a solid object with the reticle aligned with a plumb line at say 50 yds, then crank the elevation turret through its range and watch the cross hairs consistently drift off the plumb line to the left or right, is it time to send it back for realignment? How much mis-alignment is considered allowable?

I guess this is why some are willing to pay up to $3500 for a scope so they don't have to worry about these issues! Buy once, cry once.

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Originally Posted by Texas10

I see the logical progression of your steps in setting up the scope, Lonewolf. And i've used many of the same steps however, I still get groups moving off axis as I crank in elevation. So my question is this: After going through all your set up steps and tall target confirmation, what do you do if, for example you find that cranking in 25 moa of elevation also produces 3.5 minutes of left windage? Do you cant the scope clockwise to compensate? Send it back for reticle alignment? Which variable in the mounting and confirmation process do you focus on to find and fix the problem?

If I mount the scope to a solid object with the reticle aligned with a plumb line at say 50 yds, then crank the elevation turret through its range and watch the cross hairs consistently drift off the plumb line to the left or right, is it time to send it back for realignment? How much mis-alignment is considered allowable?

I guess this is why some are willing to pay up to $3500 for a scope so they don't have to worry about these issues! Buy once, cry once.

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I think your last statement hits the nail on the head. If you are trying to be successful in long range. Especially when it matters more (i.e. Competition, Hunting, etc.) then you should look for the highest level of quality you can afford. Pick the line of scopes the company stands behind with the most authority. I've ran Vortex, NF, and now shoot for Bushnell. As far as bang for your buck Bushnell is pretty hard to beat. I've been very happy with both my HDMR2 and XRS2. I never had an issue with my Ge2 Razor, or the ATACR F1 I borrowed for a bit.

So to answer your question I would definitely send that scope back whether for return or repair. Now if it's a $200 scope... Can you really be that upset if it's not perfect? You pay for quality & reliability in this industry. Especially in the optics department.

Here's an interesting article that turned up with a little more searching.

http://www.arcanamavens.com/LBSFiles...ScopeChecking/