Gunsmithing Scope level to a rifle

madpat

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Minuteman
Nov 3, 2017
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I have a Precision Extended Cantilever mount (1 piece) and I'd like to install it on AR10 - DB10 but I have a problem. I can't mount a scope leveled to a rifle properly (without cant). Do you have solution for it?

I have an Arisaka Optics Mount Tool but it won't works for me - surface on mount is too small imho.
 
Hang a string at 100 yards with a weight on the end and level your crosshair to that. Level with gravity is really what we are after anyways, this makes it easy with less fuss.

Image result for string on rock
 
sometime shims or feeler gauges work for getting it close.

s-l300.jpg


if that doesn't work, two small levels, one on the rail and one on the scope turret.
the important thing is the reticle being plumb when you are in position to shoot in your natural firing position.
 
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level the rifle - lay a level sideways (perpendicular to) on the rail out in front of the scope.
plan b is lay the level on the tops of the bottom rings, but need to ensure the gun doesn't move when you remove it and mount the scope.
plan c if you don't have a flat surface on the rifle is hold the level vertical (ie plumb) along the buttstock screws if you have them (ie a hunting rifle or the like).

level the scope - lay a level sideways (perpendicular to the rail/barrel) on the elevation turret.
plan b is use the string method above, making sure of course the rifle stays level/plumb. and/or align reticle with a fence post, deck rail baluster or something you know to be plumb.
 
I know absolutely nothing, as in nothing at all compared to 90% of the people here, so please consider this when reading me.

It seems there are 2 camps here.

1 - Get that scope aligned with the rail of the rifle within half an arc-second, and make sure when you shoot your rifle is aligned to gravity within a quarter arc-second and you are good to go.

2 - Nail down your shooting posture and body mechanics, adjust your rifle as best is possible to fit you, then hang a string out at 100 and align your scope to that, for the most part ignoring if your rifle is perfectly level (within reason) because it really doesn’t matter as long as it is consistent.

Now, again, I know jack shit. This isn’t meant as a statement of fact, just a description of what I have interpreted here and elsewhere. By all means, anyone who thinks I am way off here, please, please, set me straight.

That being said, after switching to camp #2, my shooting seems much improved. I assume this has to do with NPA, as my rig has no adjustment for cant, and I was fighting my natural inclination to (very slightly) cant my rifle due to the shape of my shoulder pocket.

It makes sense to me this way. NPA is easily in the top 2 or 3 for most important in everything I have been read or taught. Chasing a bubble level around seems counterproductive. They can be useful for reference (ensuring repeatability and whatnot) but maybe having that rifle dead plumb just plain isn’t that important as long as you properly allow for it.
 
This is not what you all think

Adding 6 levels is a waste of time,

The bullet only cares about gravity, the scope reticle needs to be leveled to gravity, nothing else, because most will move it with thier hold anyway.

Level the reticle to the fall of gravity, which the manufacturer uses the flat on the bottom of the scope, so you can match the flat of the bottom of the scope to the flat of the rail, You are DONE.

These levels you all are buying are JUNK !
and a waste of time any money

Don't over complicate it

I moved my downloads so I don;t have the image with all those bubbles being off but I can find it
 
Level the reticle to the fall of gravity, which the manufacturer uses the flat on the bottom of the scope, so you can match the flat of the bottom of the scope to the flat of the rail, You are DONE.

These levels you all are buying are JUNK !
and a waste of time any money
i guess i'm not confident on getting a 100% flat to flat. if the shim, or whatever is used, is a little too tall, then of course the scope won't be seated properly. if the shim is a little too short, then there is possibility of cant in the scope.

i use my stabila levels. def not junk. level on the rail, level on the turret, done.
 
Not to split hairs here - since I agree with everyone on aligning with gravity but... What you really need is the elevation erector to be in perfect alignment with the cross hairs, which are then aligned with gravity.

If your reticle isn't aligned with the erector movement for some reason (aka, my cross hairs don't seem to line up vertically with my scope body), if you come up 5 mils on the dial, that will have left right shift versus if you held over only. Only one of them can be "correct" if they aren't parallel to each other within the scope
 
For people that want to level their reticle indoors, do yourself a favor. Get a butler creek objective lense cap for your scope, get the correct size lense from the Indoor dry fire training system (google it, real nice dude from Canada). Hang a plumb bob about 12 feet in front of you, put your paralax around 35-40 yards, and that plumb line is as clear as a bell and easy to line your reticle with. Get the rifle prone and comfortable to you, line your verticle stadia (spl?) in line with the plumb line, and tighten your scope caps. If you dont have access to distance to do level your scope, this is an easy way to do it indoors. Plus, you can use the lense and scope cap to do dry fire in your house!
 
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Just to reiterate what others have said but not in this specific way:

Your scope absolutely has to be level to gravity. Your scope may not be level to your rifle when mounted level to gravity because you may not naturally hold the rifle perfectly level.
Scope has to be level to the fall of gravity when your in position period hard stop. It’s really not that complicated.
 
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I need the image of the levels all stacked up and off, I have to find it

YOu all falsely believe the rifle and the scope will be square to one another and that is just not how it works.

Leveling the rifle is an absolute waste of time

You can argue OCD, it's stupidity and a waste of time

A string with a weight, align the reticle and you are done

these excuses are comical, it's ignorance on display
 
thank you all for reply :)
I'll just mount scope on my AR10 and level it using engineering plumb

what do u think about SPHUR mount with built-in level? is unusable until we check gravity level and see where is a buble I think, Am I right?
 
thank you all for reply :)
I'll just mount scope on my AR10 and level it using engineering plumb

what do u think about SPHUR mount with built-in level? is unusable until we check gravity level and see where is a buble I think, Am I right?
1. Loosely place spuhr mount on rail with top rings removed.
2. Place scope in the rings, check eye relief. Attach other ring halves and slightly snug to where scope does not move foreward or aft.
3. Tighten rail bolts
4. Keep spuhr wedge underneath scope to keep it close to level with the action/pic rail. (this part doesn't really matter)
5. Use plumb line to keep reticle level. While keeping it level, slowly start tightening spuhr mount rings in typical tire-rotation fashion.
6. Once torqued to spec, verify once again that reticle is level with plumb line.

That's all there is to it.
 
thank you all for reply :)
I'll just mount scope on my AR10 and level it using engineering plumb

what do u think about SPHUR mount with built-in level? is unusable until we check gravity level and see where is a buble I think, Am I right?
I think you may be missing that it doesn’t matter if the rifle is level to the scope. If you use a bubble level on your rifle and intend to shoot with the rifle level, then it matters that the scope matches the rifle. But what actually matters is that the reticle is level with the earth when you dial elevation on your scope. As long as your reticle is level it doesn’t matter if the rifle is slightly canted.
 
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I need the image of the levels all stacked up and off, I have to find it

YOu all falsely believe the rifle and the scope will be square to one another and that is just not how it works.

Leveling the rifle is an absolute waste of time

You can argue OCD, it's stupidity and a waste of time

A string with a weight, align the reticle and you are done

these excuses are comical, it's ignorance on display

not quite all.
the OP wanted his scope and rail parallel, so i attempted to help.

but i clearly said the important thing is having the reticle plumb when you are in your natural firing position (ready to pull the trigger).
the important thing is the reticle being plumb when you are in position to shoot in your natural firing position.

even if you use a bipod and cant adjustment to force the rifle to sit level, when you pull the trigger, the stock is going to push into where your shoulder pocket wants it go (what i called the natural position).
 
When the gold standard Spuhr Mount gives you a tiny tool, a wedge to hold the scope straight in the mount while you tighten it, many people would call that a clue.

The wedge is a straight edge that matches and mates the flat of the rail (mount in this case) to the flat of the bottom of the scope. If your $450 mount supplies a $1 wedge I think we all can understand what we are looking at.
 
If you can get two of those cheap ass Chinese mini-levels to match, exactly, buy a lotto ticket. I gave up after buying like 6 of them from the same store at the same time, and none were the same on a level surface. After that I said, fuck it, let me listen to the guys with more experience and used a string tied to a brick. Is that tactical as fuck or what :)
 
If you don’t like string to a brick method, there’s always the Uber tactical sharpie on cardboard too. I also shine a light through the reticle against the cardboard since my home isn’t open enough in any area
 
I busted my balls using a couple grand worth of precision machine levels and got everything as perfect as I possible could. Then I actually learned WTF was going on, from people a lot smarter than me, undid it all, and used a damn piece of string and a water bottle.

When it comes to my groups, piece of string trumps precision levels. One day at the range and I was sold.
 
The issue people are not getting and that is demonstrated in this thread with the "tools" necessary to level the scope. It's not the scope on the rifle that is the issue, it's you the shooter.

Nobody has an issue with the scope being aligned to the fall of gravity because it is pretty forgiving. The flat to the flat is all that is really needed. Manufacturers install the reticles based on this flat. If you sent the scope back to the manufacturer because you believe the reticle is canted, they are just gonna test it versus the flat.

Where canting and all this comes from is the Shooter...

It's the Shooter's position, as well as the subconscious part of our brain that controls this aspect of it. We cant the rifle and having a scope that is aligned to the rifle is the biggest problem. Let me explain this...

Because too many are more interested in buying the levels or the wheeler mounting tools, everyone thinks, "If I spend an hour leveling the scope to the rifle" I am all good. Then they ignore the fundamentals of marksmanship and have no idea about the mechanics of a shot. They push too hard with their head because they are sideways behind the rifle, that causes a cant. They pull the bolt over and that cases a cant, they have a loose bipod with next to no resistance to any of this, which pulls the rifle over causing a cant. Rarely is a cant from the scope and rifle relationship, because if it is, the reticle is probably crooked in the scope by more than the minimum spec. Most companies will admit to 2 degrees, which is just noticeable.

If you use the flat, and they check the reticle with a plumb that will tell you everything you need, and will work perfectly. If you align the flat to the rail, and the reticle appears canted, you have an mechanical issue.

Canting the rifle comes from the shooter, no amount of work on the scope and rifle relationship will change that. In fact, it has the potential to make it worse.

If people understood their body position and subconscious mind better, they would understand this more. Instead of paying attention to the Toys out there, pay attention to the fundamentals. Investing your level money on a better bipod will have a direct result on combating a cant vs a level scope. A level scope on a level rifle that is subconsciously canted will give you 10x the error factor vs knowing what the proper body position can accomplish. It's literally a 1/2" at 1000 yards vs almost 11 Inches when you set the rifle up to you vs just defaulting to a level system.

You are the factor, it's the nut behind the bolt, not the scope.
 
When I was a general gunsmith I used a little fixture https://images.app.goo.gl/qBF3NfaS48KYEonJ6 that would align the reticle to bore it seemed to work fine. Some lever actions and some old military rifles that have off center mounted scopes are trickier. The string and weight thing works without having to buy crap. Lowlight is right, that stuff is in your head.
 
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I use the badger dead level and a plumb bob. Level with the cant of the base, level with gravity. I check/compare the bubble level built into in the Badger base with a Starret bubble level.

Shine a flashlight through the objective of the scope, project the reticle onto the wall right by the perfectly level hanging line.
54247623_249448115996371_8196706451308353312_n.jpg
 
I use the badger dead level and a plumb bob. Level with the cant of the base, level with gravity. I check/compare the bubble level built into in the Badger base with a Starret bubble level.

Shine a flashlight through the objective of the scope, project the reticle onto the wall right by the perfectly level hanging line.View attachment 7222184
that's cool.
 
I use the badger dead level and a plumb bob. Level with the cant of the base, level with gravity. I check/compare the bubble level built into in the Badger base with a Starret bubble level.

Shine a flashlight through the objective of the scope, project the reticle onto the wall right by the perfectly level hanging line.View attachment 7222184
This!!! I used to overthink leveling out the scope with tools until I learned this method. Easiest and fastest way to level it true to gravity
 
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I grab an old parting blade from my lathe tooling, stick it between the scope flat and base. Turn the parting blade at an angle, and if the ring caps are loose, the scope levels itself.

Adjust the scope until the top edge of the parting tool is flat against the scope, and the bottom edge is flat against the base.

It takes a couple seconds and works with every scope I've ever mounted. The parting blade fits in almost any size gap. Turning it at an angle fills gaps up to the size of the parting blade.

HSS parting blades are parallel to within a couple ten thousandths of an inch and a smallish 3/8 or 1/2 inch blade can be picked up on ebay for a couple dollars.
HHIP 2000-1002 3/32 x 1/2 x 4-1/2 Inch HSS Cut-Off Blade https://www.amazon.com/dp/B00N4041LW/ref=cm_sw_r_cp_apa_i_6WtgEbM1MKZP9

Ive used carbide indexables for parting the last 10 years. The only thing my HSS blades have been used for is leveling scopes.





 
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It’s impossible to level off of anything on the scope, rings, bases. To put it into perspective, 1 MOA is .000291” per inch. Absolutely no one is going to hold anywhere close to that dimension of tolerance for anything gun related. How can you expect to use a level across a scope cap or even smaller yet a turret, even the picatinny has less than “1 of bearing surface to place a level on. 20MOA is .00582”, I doubt any of the scope levels hold to that tolerance. Why waste time with all the levels when all you need is a plumb line.
 
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How do you address cant of the rifle in hunting applications where your looking at say a rock face and horizontal lines are not necessarily visible to the shooter? This is what’s always confused me on these levels. I’ve just always did what frank mentioned and used feelers under the “flat” of the scope and torqued it down there. I also use a us optics level on the rail which to me seems like the incorrect method after reading this thread.
 
if you do invest in a level to shoot with, which I don't recommend, but many people want them hanging on their rifles.

Only invest in the scope tube mounted levels.

Most people in field applications will try to follow the level when they cannot "see" the horizon, which I have no clue who shooting looking at or matching a horizon line. I cannot see the horizon with any of my targets except the furthest ones. I go by feel of the rifle in my shoulder pocket. But addressing the rifle the same way every time you have an advantage of not having to hunt or look for level, you know you are level.

We have 4 levels in our head which allow us to walk upright and do crazy shit like balance on a slackline over a canyon without falling off. This goes back to my recent post on SH where Regina Milk had problems with her scope "appearing" off but every tool in the box said it was level. Everyone was guessing what was wrong, I said she had a head cold, and sure enough, a doctor found an infection in her sinus.

If the rifle is in the shoulder pocket or at least shouldered the same way every time when moving to locations like Here in the Mountains, you should not need external reference points to use.
 
Reminds me of a time about 10 years ago at Thunder Valley Precision when I had a really bad day. I felt funky all day and the rifle never felt level....never felt comfortable. The next day I was taken to the hospital because my face went slack...I had a Bells Palsy. Took me a few weeks to get to where my rifle felt correct....I had time off from work...wanted to practice dry firing....but couldn't because it felt alien to me.
 
I use the badger dead level and a plumb bob. Level with the cant of the base, level with gravity. I check/compare the bubble level built into in the Badger base with a Starret bubble level.

Shine a flashlight through the objective of the scope, project the reticle onto the wall right by the perfectly level hanging line.View attachment 7222184
The flashlight projection is a great idea.
 
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Reading over this resurrected thread got me thinking. And that's not always the best place for me.
It's obvious that the only thing that matters is that the reticle is level when the shot is taken. The rifle could be canted a few degrees and as long as it was zeroed in that position with a level scope and therefore reticle, all is well. Given this, would it pay to get behind the rifle and get set up to the most naturally repeatable position. If that means the rifle naturally cants to the left 2 degrees every time you shoulder it, then lock off the bipod in that position, level the reticle, and know that when subconscious takes over and the rifle Comes to rest in that natural position of cant, the scope will be good to go. Otherwise we are fighting the tendency of a natural cant to make sure things are level.
If I set up to the rifle with my eyes closed in a variety of positions, and find that it's my natural tendency to cant a few degrees in one direction and that it happens every time, it seems to make sense to just level the scope based off that bit of cant. Obviously I'm the only one that can shoot the gun well at that point. Now I'm curious to go out and build a position like 5 times in a row and see if this naturally happens if if I'm not watching my tube level. And if so is it the same every time.
Sort of like the whole reason British gun fitters use a ”Try Gun” with all of it's adjustments to create a stock that fits. These stocks take into account our natural body shape and tendency so that a set of iron sights or bead will always be level for the person the rifle or shotgun was built for.
Just some rabbit hole food for thought after a long day of staring at guns through a microscope.
 
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Reading over this resurrected thread got me thinking. And that's not always the best place for me.
It's obvious that the only thing that matters is that the reticle is level when the shot is taken. The rifle could be canted a few degrees and as long as it was zeroed in that position with a level scope and therefore reticle, all is well. Given this, would it pay to get behind the rifle and get set up to the most naturally repeatable position. If that means the rifle naturally cants to the left 2 degrees every time you shoulder it, then lock off the bipod in that position, level the reticle, and know that when subconscious takes over and the rifle Comes to rest in that natural position of cant, the scope will be good to go. Otherwise we are fighting the tendency of a natural cant to make sure things are level.
If I set up to the rifle with my eyes closed in a variety of positions, and find that it's my natural tendency to cant a few degrees in one direction and that it happens every time, it seems to make sense to just level the scope based off that bit of cant. Obviously I'm the only one that can shoot the gun well at that point. Now I'm curious to go out and build a position like 5 times in a row and see if this naturally happens if if I'm not watching my tube level. And if so is it the same every time.
Sort of like the whole reason British gun fitters use a ”Try Gun” with all of it's adjustments to create a stock that fits. These stocks take into account our natural body shape and tendency so that a set of iron sights or bead will always be level for the person the rifle or shotgun was built for.
Just some rabbit hole food for thought after a long day of staring at guns through a microscope.
Set it up how you like to shoot it. That little bitnit will be offset 2 degrees makes no tangible difference. It’s your gun, set it up for you, other people can buy their own.
 
The butt will naturally fall into place and feel right every time. That's the beauty of a 3-way adjustable buttstock, it can be "canted" the 2 degrees and the rifle is level. Years of smallbore and Palma shooting with metallic sights sold me on the benefit of the adjustable buttstock. Not really an issue with scopes since they can be set level regardless of the rifle position and maintain accuracy.