Leveling a bubble level...

jeffl838

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Minuteman
Feb 20, 2013
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What's the best way to level an anti cant bubble level? What I did was I got one of these Straight Shot Segway Reticle Leveler Mark III and leveled the scope the the gun, and the I got a vortex level and leveled the vortex level to the gun. The straight shot segway seems a little not level though which makes me a little nervous. Having my anti cant level not absolutely perfect kind of destroys the point of having one... THanks.
 
Wheeler makes those little levels that go in your action just make both levels match and you will be good to go. They are handy to have around too.

Waste of time & money you risk the same problem, unit being slightly off, the placement surface being off,

you want to level the reticle to the fall of gravity, a weighted string costs nothing. A 4ft level against the wall is better than using a 1/2" level resting on the rifle somewhere. Line the reticle up while addressing the rifle is the best method. Then adjust the scope mounted level to that level reticle.

The bullet only cares about the fall of gravity nothing else.
 
Waste of time & money you risk the same problem, unit being slightly off, the placement surface being off,

you want to level the reticle to the fall of gravity, a weighted string costs nothing. A 4ft level against the wall is better than using a 1/2" level resting on the rifle somewhere. Line the reticle up while addressing the rifle is the best method. Then adjust the scope mounted level to that level reticle.

The bullet only cares about the fall of gravity nothing else.
It rests in the bolt groove and has always been correct for me. There is nothing wrong with using a plum bob i just find this way correct and quick.
 
Glad it works for you, still a waste of time and money...

The kit does not just sit on the bolt groove, there is more too it... who says your rifle's bolt groove is square to your base screws, or every rifle's action is square. You are paying money for a leap of faith.

The rifle level to the scope is not the priority, the scope level to the fall of gravity is. if your rifle is out of square and you level the scope to that, (or a bad level to start with) you are adding to the problem, not fixing it.
 
On a side topic, I have been looking at a few different scope levels, what do you guys think? Horus, vortex, NF? I was leaning towards the Horus because it also has an angle slope indicator built into it??? I already have the US optics that is mounted on the rail however I think that was a mistake to purchase. As I have read on several different posts and as lowlight just stated who says if your rail or any part of your rifle for that matter is Square, all that counts is that your scope is level to the fall of gravity. So what do you guys think about the Horus option?
 
In my experience in fabrication and machine shops,
1) most levels are questionable in accuracy
2) most people can't read a level very well
3) when you drop a level that you knew was true, you have to re-verify it
4) keep your true levels and treat them well

I picked up the level pictured below off a discarded Test & Measurement microscope. It's a machined surface on the bottom, very easy to read because it has three circles (internal point, black ring and bubble) which will line up concentrically when you have it dead nutz.
I put it on my rail, level everything from there, then align the vertical reticle to a plumb line at 25 yards.

One of these days a scope manufacturer will internalize an electronic level to a scope where you will see two arrows line up in your view when you are level. That will be the cat's pajamas!

Level.JPG
 
On a side topic, I have been looking at a few different scope levels, what do you guys think? Horus, vortex, NF? I was leaning towards the Horus because it also has an angle slope indicator built into it??? I already have the US optics that is mounted on the rail however I think that was a mistake to purchase. As I have read on several different posts and as lowlight just stated who says if your rail or any part of your rifle for that matter is Square, all that counts is that your scope is level to the fall of gravity. So what do you guys think about the Horus option?

The line of sight of your scope, your mount and your bore axis are at slight angles from each other. The one you really care about is the plane created by the axis of the scope and the bore. BUT, if the axis of your mount is not square and not in the same plane, you are starting from a cock-eyed place, as Lowlight suggests. As precisely as you can, line up the bore and mount, then go from there.
 
I may be a bit backwards, but I always put a level on top of the elevation turret, level that one out, then move the scope-mounted level accordingly. I'll have to test it against a plumb-bob next time I'm home.

My thoughts were that the reticle may be canted, so holding square to a (possibly) canted reticle, and adjusting my elevation will result in a very small azimuth shift. Leveling to the turret should remove the possibility of azimuth shift from elevation turret cranking-- Assuming the turret is machined and installed squarely. So I guess you can either hope that your elevation turret is machined squarely or that your reticle is not canted.

I do agree that it's nearly pointless to put a level not directly onto the scope tube.

I for one, have never been a guy to use feeler gauges or whatever else to perfectly square my scope to the rail it's mounted on. I eyeball it, then install the level accordingly. The minute horizontal offset from bore center axis from me mounting my scope slightly crooked to the rail is neglible IMO. What is important is that the optic (more specifically the elevation adjustment) is accurately level to gravity.
 
Waste of time & money you risk the same problem, unit being slightly off, the placement surface being off,

you want to level the reticle to the fall of gravity, a weighted string costs nothing. A 4ft level against the wall is better than using a 1/2" level resting on the rifle somewhere. Line the reticle up while addressing the rifle is the best method. Then adjust the scope mounted level to that level reticle.

The bullet only cares about the fall of gravity nothing else.

What he said. Gravity works the same on a plumb-bob as it will on your bullet. Then, to really make yourself feel confident, do the following:
1. Set up a good paper target at 100 yards.
2. With a zeroed scope, shoot a three shot group, dial 10 minutes up, shoot a three shot group, dial 10 minutes down (from zero), and shoot another three shot group.
3. Walk up to your target and hang the plumb-bob. If you did it correctly, and your scope tracks true, the string should drop right down the middle of each of the three groups.
4. Now you know that your scope is level, level, level.
 
Ok , so when using a plumb line
How can we makesure the rifle is level to begin with?

Kyle

Let me ask you this, What does it matter whether the rifle is level or not?

As long as the scope is level, elevation adjustments will only affect elevation, regardless of how canted the rifle is.

If the scope is canted, the crosshairs will move down and to one side just by cranking only the elevation knob.

If the rifle is canted and the scope is level, you will have a very very small horizontal shift, but it will be a fixed ratio. For example, the M1D Garand. The scope is mounted roughly 2" to the left of the bore center axis (as well as a fair bit above it, but since our scope is level, the elevation turret fixes that and we need not worry about it). I don't know exactly how far left of center, so I will just use 2" for this example. At point blank, POI is 2" right of POA. At your 100yd, POI is 1" right of POA, at your 200yd zero, POI is POA, at 300yd, POI is 1" LEFT of POA, at 400yd, POI is 2" left of POA. etc. etc. At 800yd, POI is 5" left of POA.

Let's look at the other side of things. Assume your scope is 3" directly over your bore, zero offset, however your optic is canted 5 degrees. I'll use generic ballistic data, .308 175smk @ 2550fps 29.92 in/Hg, 59 degrees.

At 800yd, I'll save you the trig, but at 5 degrees offset, your bullet will hit just a couple inches low, and 19-20" to the left/right of where you were aiming.

So yeah, ideally your scope would be level, and directly over your rifle's bore. That doesn't necessarily mean your rifle is level, and the way you hold your rifle, it may not be comfortable to hold it directly level. The point is that it's really not that big of a deal (extreme example of 5/8MOA shift at 800yd). What's important is that the scope is level.

edit: I'll be even more specific. The elevation turret is what you want leveled to gravity, because it directly adjusts for gravity's pull on the bullet. Everything else is an after-thought. That is, unless you use the reticle for hold-overs, or a BDC type reticle and don't touch the turrets, then it's important to level the reticle. It's very possible that the reticle and turrets are square to eachother, but I don't make that assumption until I've proven whatever scope I'm using.
 
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For what it's worth, I set mine (vortex level) up with the wheeler kit. I've shot it out to a thousand yards and only had to dial in windage for wind and spin drift. I used the level in the bolt raceway, one on the NightForce rail, and another level on the elevation turret. When they were all level I leveled the Vortex bubble, and called it a day.

That said, I don't have to take shots at unknown distance or anything like that, but it did work for me. I will agree that a plumb line is probably a more precise way of going about, as the weighted string does not lie and can't be off.
 
About as simple as it gets.

Hang a plumb bob or a carpenter’s yard stick that is plumbed with a level straight down

Square up the scope reticle level with plumb bob.
Match the level mounted on the scope next

While at it crank the turret up and down to see if it travels square with the edge of the plumb bob hanging and all is done

Gravity pulls the plumb straight down as well as the bullet

While you’re at it, calibrate your scope to see if it actually does what it claims to do



oneshot.onehit
 
Glad it works for you, still a waste of time and money...

The kit does not just sit on the bolt groove, there is more too it... who says your rifle's bolt groove is square to your base screws, or every rifle's action is square. You are paying money for a leap of faith.

The rifle level to the scope is not the priority, the scope level to the fall of gravity is. if your rifle is out of square and you level the scope to that, (or a bad level to start with) you are adding to the problem, not fixing it.


Wouldn't you want the rifle to be level to the scope? If so, what's your method of leveling the rifle to the scope without using a "1/2" level"?
 
Ok , so when using a plumb line
How can we makesure the rifle is level to begin with?

Kyle

Most rifles' butt pads are secured with two screws. Line up the screws parallel to a plumb line and the rifle should be about as good as you can get it without having to do backflips. If the holes are very small, insert toothpicks into them to get a better reference. Once the rifle is level, do the reticle leveling with a plumb line as per LL. Check the reticle/rifle relationship as per bmk.

Plumb=plumb=plumb/level=level=level.

Keep in mind that even the most perfectly leveled rifle/reticle is still only as good as the shooter who is using the system.

Greg
 
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Feeler gauge and a plum level. Total cost $5

Use the feeler gauge to level the scope on your base. Set a plum level (string and weight) at 50-100 yards to place your bubble level on your scope tube.
 
LL was the first person i read using the feeler gauge method.

You can buy feeler gauges at almost any auto parts store. They are used for adjusting valves and what not like that.
The idea is that the base is level with the bore. If you have a one piece rail, the flat surface of the rail and the flat surface on the bottom of your scope can be completely parallel buy placing the correct number of feeler gauges between the two. There are several images already posted on the internet of using this method.
The more important issue is leveling the bubble level. That is when you need a plum line to verify the reticle it true. As LL said "The rifle level to the scope is not the priority, the scope level to the fall of gravity is".
 
Leveling the rifle is people's problem with canting... believe me this is where guys screw up. Our shoulder pocket does not want the rifle level. So you have to set the rifle up to your "Natural Position". After you properly address the rifle in your shoulder pocket, add the scope, and "Level the Scope" to the fall of gravity.

If you get a bubble level, and then address the rifle and find your hold is off level, that is called a clue. Use the level to diagnose your position and don't force yourself to meet up to the rifle being level.

The best level to use, is the Scope Tube Mount... rifle levels are not gonna help, unless you have an adjustable buttplate on your stock where you can adjust that to your shoulder pocket.

If you are interested in staying level - level, meaning a level rifle and a level scope, the fastest and easiest way to accomplish this is with a set of feeler gauges, a deck of cards, (same principle) or using a mount that has a key like the Spuhr. Holding the bottom of the scope (the flat) level to the base on the rifle. But again, if you are constantly adjusting because the bubble is off, you should move your scope to account for this. What happens is, you check it, you're off, you adjust, then go back to looking through the scope and will subconsciously move back to off level. Believe me I have more still images of guys I photograph who try to be "level - level" that do this than I can post in a single thread.

If you set the rifle up to your natural hold, does not matter your position, the rifle position will key off your shoulder and not the horizon, or some other thing, it will key off you... which makes that part subconsciously correct, as opposed to consciously corrected.

<iframe width="560" height="315" src="//www.youtube.com/embed/V_K9Z9KZvPE" frameborder="0" allowfullscreen></iframe>
 
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Leveling the rifle is people's problem with canting... believe me this is where guys screw up. Our shoulder pocket does not want the rifle level. So you have to set the rifle up to your "Natural Position". After you properly address the rifle in your shoulder pocket, add the scope, and "Level the Scope" to the fall of gravity.

If you get a bubble level, and then address the rifle and find your hold is off level, that is called a clue. Use the level to diagnose your position and don't force yourself to meet up to the rifle being level.

The best level to use, is the Scope Tube Mount... rifle levels are not gonna help, unless you have an adjustable buttplate on your stock where you can adjust that to your shoulder pocket.

If you are interested in staying level - level, meaning a level rifle and a level scope, the fastest and easiest way to accomplish this is with a set of feeler gauges, a deck of cards, (same principle) or using a mount that has a key like the Spuhr. Holding the bottom of the scope (the flat) level to the base on the rifle. But again, if you are constantly adjusting because the bubble is off, you should move your scope to account for this. What happens is, you check it, you're off, you adjust, then go back to looking through the scope and will subconsciously move back to off level. Believe me I have more still images of guys I photograph who try to be "level - level" that do this than I can post in a single thread.

If you set the rifle up to your natural hold, does not matter your position, the rifle position will key off your shoulder and not the horizon, or some other thing, it will key off you... which makes that part subconsciously correct, as opposed to consciously corrected.


You should repost this in a standalone locked thread and sticky it to the top of the forum. At a minimum, copy paste this text into a doc so you can save yourself the time of having to type it all again when this comes up again in a month.
 
I have been fighting this for a long time....I swear I think the reticle is level, then I look at my level and it's off! To level my reticle, I put a bubble level on the rifle, one on the elevation turret cap and then level my scope bubble level. Get behind the rifle and it looks canted! So yesterday I finally used a plumb bob, then when I got behind the rifle, it seemed REALLY canted! I must be friggin' lopsided or something. However, I am trusting what the reticle and level say though now because you can't argue with gravity.

Don't be fooled, as I have just learned that my eyes have been deceiving me all this time. What I thought was level, really wasn't. I don't think there can be a better way than to use a plumb bob.
 
Plumb line. Get a step ladder. 6' min. Tie a string, put a small sledge hammer tied to it at the bottom, just high enough to submerge in a 5 gallon bucket of water. Rifle, in a gun vise if you have it, on a rock solid table. That's the way. Line it up.
 
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Whats the best way to setup a plumb-bob to align the reticle?

ie. I can't focus my scope close enough to do it inside, and I can't see the string outside during the daytime (string washes out into the background). Any additional suggestions for the plumb-bob method? Also, is it better to zoom the scope, or leave it on the lowest power setting to see more of the reticle in comparison to the string? I ended up making a long level line (from a carpenters level) on some white paper stapled to my fence - which seems to have the same effect. However, the plumb-bob would have been quicker if I could get it to work.
 
Get a 4ft Level, attach it to your Target board with heavy duty clips, or a C Clamp, and then you can line the reticle up. They sell the bright yellow Stanley Levels for about $30...

Also you can test tracking by placing the reticle at the top of the level, (bagged in) then run the elevation up until it reaches the bottom and do the math. ( Programs like FFS has a scope calibration utility that gives you the exact click value) You can then see if the reticle followed the edge of the level, or if the scope has a slight curve to it as some scopes will have a small curve in their travel because of the erector spring style.

You can also also check your hold by having someone else dial the scope's elevation as you hold it on target. It will help you set the rifle up to your natural position.
 
Of course, using a plumb line to level your scope assumes your reticle is true to the dials. What sucks is when your reticle is canted to the dials, you're not really level. If you're a dial turner, you'll want to make sure your reticle is true to the dials. On most high end scopes this won't be a problem. Not so much at times on the marginal stuff. I find this mostly occurring on hunting scopes that weren't designed to be adjusted frequently but then folks buy a ranging knob and they find the dials don't match the plane of the reticle. If you don't use dials, then it won't matter as your holdover will be level (assuming you have a holdover reticle).
 
Why does it matter... Well it will cause big issues when shooting long range, for every 5 degrees of cant in your Rifle, regardless if the scope is level is about .1 mil off per 100 yards. you times that by 10 and you can easily miss a whole target! so it is very important to level the Rifle! Then level the scope to the rifle, leaving the rifle leveled, you will be dead on.
 
"Let me ask you this, What does it matter whether the rifle is level or not?

As long as the scope is level, elevation adjustments will only affect elevation, regardless of how canted the rifle is.

If the scope is canted, the crosshairs will move down and to one side just by cranking only the elevation knob.

If the rifle is canted and the scope is level, you will have a very very small horizontal shift"

Why does it matter... Well it will cause big issues when shooting long range, for every 5 degrees of cant in your Rifle, regardless if the scope is level is about .1 mil off per 100 yards. you times that by 10 and you can easily miss a whole target! so it is very important to level the Rifle! Then level the scope to the rifle, leaving the rifle leveled, you will be dead on.
 
What's the best way to level an anti cant bubble level?

Does this really matter? If you just stick it on and eyeball the position, then shot to shot will have the same cant, right? So suppose it's off slightly, every shot would still be off the same way the same amount. I don't have one of these but I've always thought the utility of having one is leveling the gun with a deceiving horizon or background.
 
Why does it matter... Well it will cause big issues when shooting long range, for every 5 degrees of cant in your Rifle, regardless if the scope is level is about .1 mil off per 100 yards. you times that by 10 and you can easily miss a whole target! so it is very important to level the Rifle! Then level the scope to the rifle, leaving the rifle leveled, you will be dead on.

I think you're missing the science here, a bullet doesn't know if the rifle is being held at 90 degrees to the earth or 45 degrees. The bullet is a slave to gravity no matter what and will follow the same path. What LL is saying, (I think) is that it's important to have the reticle level with the fall of gravity.
 
For a bolt action I do this, and someone please tell me if I am not doing it correctly because I have probably been screwing up for a long time.
I mount my scope base (20moa) and lock it down. Then I lock down my rifle in a vise, or on a bipod and bags and keep it level using a bubble level tube in one of the rail slots.
Then I drop my scope in the rings, and slowly tighten down the ring screws while also having a bubble level tube on the top of the scope turret knob.
And just for safe measure, I use one of these under the scope belly before tightening all the way down to make sure its completely level.
http://farm7.staticflickr.com/6110/6890632520_81f80c2c8c.jpg
 
Even if you get the crosshairs perfectly level, so what. You have to shoot the gun as you will use it to verify it's vertical with gravity. Both Holland's article, Reticle Perpendicularity and Litz's new CD will help ensure you that you, the reticle and gravity are working together
 
Well I am going to throw this one out here because I have been doing my scope level different than any of these previous post and it seems to be working good for me. After buying my first long range gun which is a cooper 7 mm mag and I pieced together a suregon 6.5 creedmore and I did it the same way. After zeroing my scope at 100 yds I then dial 1000 yds and shoot at 100 yds again with a vertical line on the target I am about 3/4" to the left of the line about 28" above the bullseye. This is supposed to compansate for the right hand twist of the barrel. My scope is canted counter clockwise with my gun being level. I am not saying this is the correct way of doing it but this is how I was taught and it seems to work for both my long range guns, one I hunt with and the other is just for competitions
 
Let me ask you this, What does it matter whether the rifle is level or not?

As long as the scope is level, elevation adjustments will only affect elevation, regardless of how canted the rifle is.

If the scope is canted, the crosshairs will move down and to one side just by cranking only the elevation knob.

If the rifle is canted and the scope is level, you will have a very very small horizontal shift, but it will be a fixed ratio. For example, the M1D Garand. The scope is mounted roughly 2" to the left of the bore center axis (as well as a fair bit above it, but since our scope is level, the elevation turret fixes that and we need not worry about it). I don't know exactly how far left of center, so I will just use 2" for this example. At point blank, POI is 2" right of POA. At your 100yd, POI is 1" right of POA, at your 200yd zero, POI is POA, at 300yd, POI is 1" LEFT of POA, at 400yd, POI is 2" left of POA. etc. etc. At 800yd, POI is 5" left of POA.

Let's look at the other side of things. Assume your scope is 3" directly over your bore, zero offset, however your optic is canted 5 degrees. I'll use generic ballistic data, .308 175smk @ 2550fps 29.92 in/Hg, 59 degrees.

At 800yd, I'll save you the trig, but at 5 degrees offset, your bullet will hit just a couple inches low, and 19-20" to the left/right of where you were aiming.

So yeah, ideally your scope would be level, and directly over your rifle's bore. That doesn't necessarily mean your rifle is level, and the way you hold your rifle, it may not be comfortable to hold it directly level. The point is that it's really not that big of a deal (extreme example of 5/8MOA shift at 800yd). What's important is that the scope is level.

edit: I'll be even more specific. The elevation turret is what you want leveled to gravity, because it directly adjusts for gravity's pull on the bullet. Everything else is an after-thought. That is, unless you use the reticle for hold-overs, or a BDC type reticle and don't touch the turrets, then it's important to level the reticle. It's very possible that the reticle and turrets are square to eachother, but I don't make that assumption until I've proven whatever scope I'm using.

On this basis somebody needs to develop a self-leveling reticle that remains vertical at all times, regardless of rifle cant.