I like the Spuhr wedge system... of course if your reticle is canted within the scope, that's another problem.
Rifle Scopes Scope leveling
- Thread starter ingraham
- Start date
What this does not address is that the reticle needs to be in line with the bore. Forgive my simple artwork, but I exaggerated the condition to illustrate a point. If the reticle isn't perpendicular to the bore, then you end up with riflescope1. Then, when you cant the scope either manually, or with a level, you still could end up as shown in riflescope2 if the scope/reticle is not properly aligned with the bore.
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You realize even with your exaggerated examples that it won't have enough of an effect to matter. It would be about the same as playing with your scope center line above the bore measurement and seeing how little difference it makes.
Edit: Btw, you can adjust that in the ballistic app if you are really that worried about it
Out to 200 yds, a slight bore/scope misalignment probably doesn't make that much of a difference. But, loosen your scope rings and play with it out to 500 yds. You might be surprised. I've seen scopes that were supposedly "aligned" with the rifle by clamping it in a gun vise and aligning the scope using a plumb bob, levels, or some other visual alignment, only to find out they would consistently shoot as much as a MOA off left or right as the distances increased. Later, only to find out that the scope reticle was not in line with the bore. Also, keep in mind that when that firing pin strikes that primer, that gun will start to move. How perpendicular you are holding it compared to the scopes perpendicular line of sight will make a difference. Another way to test this is take your favorite handgun to the range and see what the difference in point of impact is when you grip it tight, grip it loose, or hold it sideways.
Ballistic apps are nice, and I use them. But, quite often I don't have the time it takes to pull my notebook computer or phone out of my pocket and fine tune my parameters for changing distances out in the field. Whether or not the rifle bore is in line with the reticle is one variable I don't want to have to allow for.
The offset is a static number unless you are constantly fiddling with your equipment. You only need to enter it once..
And your exaggerated drawing bears no resemblance to reality. It makes almost zero difference at 500 yards. You can input various errors into the equations shown in the paper I posted earlier to convince yourself
Or we can just expand this thread with more useless information
Agreed, because the answer is simple.
If your scope reticle lines up properly with your turrets it doesn't matter if you level using shims, wedges, or a plumb bob - the end result will be the same regardless of what you do.
If you scope reticle doesn't line up properly and you can't send it in for warranty repair, you have two options.
- If holdovers are more important to you than turret tracking, level the scope with a plumb bob. Measure the horizontal offset when dialing for elevation and adjust accordingly whenever you dial.
- If true turret tracking is more important to you than holdovers, level the scope with shims or wedges. Measure the horizontal offset when using holdovers for elevation and adjust accordingly whenever you hold over.
I found this article quoted above to be very interesting. https://www.shootingillustrated.com/articles/2016/3/28/rifle-scope-reticle-cant/
However, in discussing reticle leveling, the illustrations assume you start out by having the rifle "level." Just putting it in a vise or mounting it on a bipod, etc. before you level the scope to an external plumb bob does not mean that you started out with a level rifle. Someone mentioned above a 4" error at 1k yards. The article itself talked about errors of 14" at 1k yards due to scope/rifle cant. You can record this error in your shooting table and correct for it. Of course, when you correct that variable in your shooting table at 500 yds, it will not be the same at any other distance. Or, maybe you can remedy that with your ballistics program. If your ballistics program accepts that amount of misalignment and properly compensates for it at any distance, then that's great. But, why even bother having to deal with that in the first place? Just properly align the scope reticle with the bore of the rifle and be done with it. In practical application, sometimes you don't have time to haul that cell phone out of your pocket and run the numbers before you take a shot. Consistent accuracy is all about eliminating variables whenever possible.
If you actually shoot past 600 yards, you should have a rail mounted level of some sort by now.
Step 1: buy rail level, and keep it on gun forever.
Step 2: level the gun, with your handy level that you're actually going to use in the field.
Step 3: put a flat level ontop of the turret, and twist the tube till it matches your rail level. The vast majority of >$1000 optics have the top of the turret flat perpendicular to the vertical crosshair. 1 degree off? Oh, fuck off.
Now you have your scope leveled to what you will ACTUALLY use in the field. Not some temporary thing based on faith. You can get even more silly if you want: replace Step 3 with a plumb bob weight hanging off some string- gravity ain't gonna lie. Again, now your shit is matched to what you will ACTUALLY rely on in the field.
Step 1: buy rail level, and keep it on gun forever.
Step 2: level the gun, with your handy level that you're actually going to use in the field.
Step 3: put a flat level ontop of the turret, and twist the tube till it matches your rail level. The vast majority of >$1000 optics have the top of the turret flat perpendicular to the vertical crosshair. 1 degree off? Oh, fuck off.
Now you have your scope leveled to what you will ACTUALLY use in the field. Not some temporary thing based on faith. You can get even more silly if you want: replace Step 3 with a plumb bob weight hanging off some string- gravity ain't gonna lie. Again, now your shit is matched to what you will ACTUALLY rely on in the field.
You mentioned an offset bore and that's where the 4" come from. Having the reticle canted will be a lot bigger difference. Some very good shooters run the rifle canted but mount the scope level. I believe David Tubb is one of them but that does he know.
As I said in previous posts, the proof is in the pudding. If you're getting hits at distances we normally shoot in a consistent fashion from the prone, you're doing something right. I have researched this to death and I urge you to dissect the underlying mathematics to convince yourself if you haven't already done so.
Unless you are capable of routinely shooting 0.5 MOA @ 1,000 yards, the errors from the purely bore related horizontal offsets you discuss are in the noise and you won't be able to discern your limitations from any common error or limitation in technique. It is a static error and that is why it can be removed through a ballistic solver. The effect is linear so the magnitude increases as the distance increases in a 1:1 fashion. However, if the issue is a canted rifle with a reticle that is not set to the fall of gravity, the errors are far worse and are non-linear. It is, however, mathematically deducible using simple physics and trigonometry.
Understanding the underlying math/physics allows you to properly eliminate the TRUE sources of error with your EQUIPMENT. Eliminating the humanly induced errors is another matter entirely
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You guys need to lap your rings first. You need to use powdered toilet bowl cleaner and a paper towel tube. Be sure to use long full strokes with intent.
It helps if you are standing with the butt of the gun between your legs while you are making the long full strokes.
Anyone here (besides me) used this technique to level the reticle? 
Racist!!!! ?Anyone here (besides me) used this technique to level the reticle?
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I have tried it. I saw it on YouTube.
There is no reason it won't work as long as your line is truly plumb. It works great with the Badger Dead level
There is no reason it won't work as long as your line is truly plumb. It works great with the Badger Dead level
My scope level is dead-nuts square to my turret housing.
When the bubble in my scope level is dead-nuts centered, my reticle is dead-nuts aligned to a plumb bob.
Therefore my reticle is dead-nuts square to my turret housing.
Life is good.
/end thread
When the bubble in my scope level is dead-nuts centered, my reticle is dead-nuts aligned to a plumb bob.
Therefore my reticle is dead-nuts square to my turret housing.
Life is good.
/end thread
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No,
Your are assuming it works that way for Every Scope, it does not .
Stop being That Guy that contradicts best practices for shortcuts that work only in limited situations.
Best practice is level the reticle to gravity and have the bubble match that. Why you want a level on the scope tube versus the rail.
Bad advice never ends the discussion
Your are assuming it works that way for Every Scope, it does not .
Stop being That Guy that contradicts best practices for shortcuts that work only in limited situations.
Best practice is level the reticle to gravity and have the bubble match that. Why you want a level on the scope tube versus the rail.
Bad advice never ends the discussion
Shoulder the rifle(same way), line up .scope reticle to masking tape that’s level on a outside door tighten scope then perform tall target test.
No matter what way you level your scope reticle you should perform tall target test .
Good luck.
No matter what way you level your scope reticle you should perform tall target test .
Good luck.
You are missing a very important part, the turrets are not what you use, the fact your turrets are good does not mean every person should use the turrets to level the reticle or gauge the reticle's position by.
We get it, this worked for you this time, next time it might not so why advocate or discuss something that might not be valid for all
No doubt my post #70 wasn't well written and perhaps a bit too tongue-in-cheek. It was never intended as advice, just an observation about my own scope. My apologies for any confusion it may have caused.
My final contribution to the discussion...
Throughout this discussion we have NOT established a reliable means for the average Joe to determine if his scope suffers from a canted reticle. IMO, this is a really critical piece of the puzzle for precision shooting.
I was happy to report in post #70 that I have found no discernable cant in my SWFA 10X42 HD, which leaves me free to either hold-over or dial-in elevation corrections without fear of the POI wandering horizontally with elevation corrections. I can hold the reticle level (as observed by the scope level) and know my elevation adjustment will track it accurately.
A cursory check for a canted reticle is quick and simple to do, and requires no trip to the range: hold the turret housing perfectly level (however you wish to mechanically do so) and then sight a plumb bob or other know vertical to see if the reticle is also perfectly level. If it is, great! If not, make a decision of how you're going to proceed from there (send scope back for repair, or when shooting use only hold-over with a the reticle leveled or use only dialed-in corrections with turret/tracking leveled.
Note - on my SWFA scope, using the top of the actual turret cap (as recommended by many) gave a false level. Removing the cap and using the top of the turret collar (that is part of the housing) gave a true reading. The flat on the bottom of the turret housing is another surface that can be reliably used to establish level of the of the elevation/windage adjustments.
I'll leave the discussion with a recommendation to anyone interested to read these two links, which cover all the important points in an organized and easy-to-understand fashion;
https://precisionrifleblog.com/2014/08/22/tactical-scopes-mechanical-performance-part-2/
https://precisionrifleblog.com/2014/08/13/tactical-scopes-mechanical-performance-part-1/
Happy shooting!
Just adjusted hunting rifle with BDC reticle to plum to fall of gravity to negate natural cant induced by pec muscle while shooting positional. I don’t dial this scope much as the reticle is on for my load out to 800 in most conditions.
Something now looks broke with the mounting when standing back off the rifle. But damn if it’s not impressive how the reticle falls plumb every time no matter how fast I throw the rifle into my shoulder.
Something now looks broke with the mounting when standing back off the rifle. But damn if it’s not impressive how the reticle falls plumb every time no matter how fast I throw the rifle into my shoulder.
A tall target test is what tells you it's not canted,
That and the flat at the bottom, we said this why is it so hard to figure, it was all mentioned.
The reticle is aligned to the flat so you can gauge the spec
That and the flat at the bottom, we said this why is it so hard to figure, it was all mentioned.
The reticle is aligned to the flat so you can gauge the spec
Instead they references a guy that knows enough to be dangerous, charts and graphs make all the difference. We should all just bury the ocular then wonder in writing why the magnification is off, genius
Ya you seen me use all of those
Flat to flat whatever you have.
For your kit I like feeler gauges but the other stuff works too
Flat to flat whatever you have.
For your kit I like feeler gauges but the other stuff works too
Is there a point where cant built into the orientation of the rifle to conform naturally to the shoulder pocket become excessive? I’ve got big pecs compared to my frame size and the rifle wants to sit best I can guess upwards of 5-6 degrees offset from the reticle with reticle aligned to the fall of gravity.
Feels great, shoulders great, am able to get real relaxed behind the rifle. I should get out and shoot to verify but don’t have a long range readily available to observe any potential errors in my setup.
@lowlight @Nik H I think what you guys are saying is to:
The rest of this post is not really related to first part.
A side note on the EXD tool: it seems to work well for me, but keep in mind the tool's assumptions: the rifle bore is dead center of the barrel AND the ocular housing is concentric to the scope's optics. And, if I read lowlight/Nik H ‘s advice above correctly, the reticle/bore axis cant doesn’t really matter too much.
The best illustration of canting effects was an interactive tool I found by google searching, post #12 here: https://www.airrifle.co.za/threads/12512-The-result-of-canting
direct link: http://www.arld1.com/images/swfs/impactpointvscantangle.swf (it's a flash file, you'll need a flash player to use it https://get.adobe.com/flashplayer/)
I am NOT saying canting matters much, only that this interactive tool showed me how it affects the shot. I do not vouch for it's accuracy, and I ignored the "compensation control" button.
- ignore the cant of the reticle/bore axis because:
- the error that it creates is not great at distances most people shoot at
- if you suspect that rifle/bore axis cant is a problem, since the effect is linear, one can fairly easily discover the problem (and compensate for it). Although, I'm noob enough to not know accurately do either.
- get the rifle in a comfortable position with your body
- get the reticle level to gravity (i.e. plumb line)
- go shoot
The rest of this post is not really related to first part.
A side note on the EXD tool: it seems to work well for me, but keep in mind the tool's assumptions: the rifle bore is dead center of the barrel AND the ocular housing is concentric to the scope's optics. And, if I read lowlight/Nik H ‘s advice above correctly, the reticle/bore axis cant doesn’t really matter too much.
The best illustration of canting effects was an interactive tool I found by google searching, post #12 here: https://www.airrifle.co.za/threads/12512-The-result-of-canting
direct link: http://www.arld1.com/images/swfs/impactpointvscantangle.swf (it's a flash file, you'll need a flash player to use it https://get.adobe.com/flashplayer/)
I am NOT saying canting matters much, only that this interactive tool showed me how it affects the shot. I do not vouch for it's accuracy, and I ignored the "compensation control" button.
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I don't focus too much on 1 as the examples Lowlight provided in the original post prove the point.
2-4 are what I took away from it all. Your position behind the rifle is critical. You need to be comfortable or you will be unconsciously muscling the rifle. Aligning the reticle to be plumb while it is in position is very important to minimizing the cant error.
Shooting is the most important
2-4 are what I took away from it all. Your position behind the rifle is critical. You need to be comfortable or you will be unconsciously muscling the rifle. Aligning the reticle to be plumb while it is in position is very important to minimizing the cant error.
Shooting is the most important
Here are the math examples, as I hate we keep going into the weeds, but two parts here:
1. Canting as a problem is not usually because of mounting, and you can absolutely mount a scope off-axis and it will work. Canting is from the bipod and Shooter Interface, their body position which rolls your head over and then bringing the rifle with you.
We do not cant the rifle because of how you mounted it, unless the reticle is canted inside the scope. If you mount the scope off the exterior and not the reticle, you can have an issue, doesn't mean you will, but you increase the chances.
2. Watch the recent video I did and understand Jeff in the video shot a great group at 100 yards. Sub 1/2 MOA. But look at the wrestling with the rifle. When he runs the bolt he has to straighten out the rifle every single time. This is where canting comes from.
Anything inside 2 degrees can easily be overlooked by the shooter, by that I mean they can miss the cant in the reticle. The examples of 5 degrees are absolutely positively stupid on every single level imaginable because it is highly noticeable. Nobody with a 5 degree of accidental cant is going to think it looks straight and if they do they have bigger problems. This error is usually tiny comparatively speaking, under 2 degrees.
So first here are why you can actually cant a scope or have it turned in the rings for proper tuning and set up,
This outlines why setting it up correctly for the shooter is smarter, because as I have said until I have turned blue in the face, we don't have an issue mounting, we have an issue shooting.
Now this video is about trigger control, but look at the lateral movement in this video. It is where canting comes from,
Finally I did a video many years ago where I set up two identical scopes with one mounted straight to the receiver and one canted for my natural hold. The groups at a 1000 are equally awesome and regardless I was able to stay on the plate doing it either way, It's why even at distance it doesn't matter. For an FYI my personal cant is about .8 degrees,
I know we we won't put this to bed here, but understand, those who advocate devices to mount, and level, etc are trying to sell you a product and not fix your problem. Me on the other hand, I have nothing to sell you but knowledge. The origins of a cant have very little to do with mounting.
Stick a set of business cards or feeler gauges under the scope between the rail and match the flat of the rail to the flat of the scope. Check it with a plumb line and you are in business. If you want an ADVANCED TECHNIQUE for improving this process, you add in YOUR personal, natural hold of the rifle, one that feels comfortable, and then level or true the reticle to that hold. That is it, you either mount level scope to a level rifle, and it really is not that hard, or you take the time to set up the rifle to the shooter and then level the reticle to gravity. In this case, a scope tube mounted level can be used to confirm the position is correct. There is training required because if you mount a level on your rifle and every time you check prior to the shot, you find the level is off-center, you have a rifle set up problem, TRUE your rifle to you to fix that as the level is giving you a clue.
1. Canting as a problem is not usually because of mounting, and you can absolutely mount a scope off-axis and it will work. Canting is from the bipod and Shooter Interface, their body position which rolls your head over and then bringing the rifle with you.
We do not cant the rifle because of how you mounted it, unless the reticle is canted inside the scope. If you mount the scope off the exterior and not the reticle, you can have an issue, doesn't mean you will, but you increase the chances.
2. Watch the recent video I did and understand Jeff in the video shot a great group at 100 yards. Sub 1/2 MOA. But look at the wrestling with the rifle. When he runs the bolt he has to straighten out the rifle every single time. This is where canting comes from.
Anything inside 2 degrees can easily be overlooked by the shooter, by that I mean they can miss the cant in the reticle. The examples of 5 degrees are absolutely positively stupid on every single level imaginable because it is highly noticeable. Nobody with a 5 degree of accidental cant is going to think it looks straight and if they do they have bigger problems. This error is usually tiny comparatively speaking, under 2 degrees.
So first here are why you can actually cant a scope or have it turned in the rings for proper tuning and set up,
This outlines why setting it up correctly for the shooter is smarter, because as I have said until I have turned blue in the face, we don't have an issue mounting, we have an issue shooting.
Now this video is about trigger control, but look at the lateral movement in this video. It is where canting comes from,
Finally I did a video many years ago where I set up two identical scopes with one mounted straight to the receiver and one canted for my natural hold. The groups at a 1000 are equally awesome and regardless I was able to stay on the plate doing it either way, It's why even at distance it doesn't matter. For an FYI my personal cant is about .8 degrees,
I know we we won't put this to bed here, but understand, those who advocate devices to mount, and level, etc are trying to sell you a product and not fix your problem. Me on the other hand, I have nothing to sell you but knowledge. The origins of a cant have very little to do with mounting.
Stick a set of business cards or feeler gauges under the scope between the rail and match the flat of the rail to the flat of the scope. Check it with a plumb line and you are in business. If you want an ADVANCED TECHNIQUE for improving this process, you add in YOUR personal, natural hold of the rifle, one that feels comfortable, and then level or true the reticle to that hold. That is it, you either mount level scope to a level rifle, and it really is not that hard, or you take the time to set up the rifle to the shooter and then level the reticle to gravity. In this case, a scope tube mounted level can be used to confirm the position is correct. There is training required because if you mount a level on your rifle and every time you check prior to the shot, you find the level is off-center, you have a rifle set up problem, TRUE your rifle to you to fix that as the level is giving you a clue.
^ 100 * 10 %
This should be a locked thread and everyone needs to follow Frank's suggestion to FINALLY get rid of this topic.
This should be a locked thread and everyone needs to follow Frank's suggestion to FINALLY get rid of this topic.
I was skeptical until I broke down and decided to give it a try. It’s awesome.
I know this doesn't necessarily apply to bench-rest shooting, but there are things I look for to tell me whether or not I'm canting the rifle before I shoot. I do go to great lengths to mount the scope level and perpendicular to the bore axis. Now, I understand that Lowlight says this is not as important as eliminating overall shooters cant, and I agree. But, before I pull the trigger on that long range deer, coyote, or hog, I look for other things in the scope to tell me whether or not I have the rifle perpendicular or canted. The horizon, tree trunks, fence posts, etc. are all things I check through the scope to tell me whether or not I'm holding the rifle straight and level and not canted. I've done it this way so long that when I occasionally sit down at my shooting bench and shoot over a bag at 1,000+ yds, I usually don't have cant issues.
Man good stuff. Got a plumb line hanging from a tree limb with a big socket tied to it. I'm sure I'll need to adjust my scope.
I have a scope level on my scope tube and it seems I always have to jockey the rifle before I shoot to get the scope level to indicate level.
Tells me I'll have to rotate my scope some to the plumb line when I have a good comfortable mount of the gun in my shoulder pocket ,then re- level the scope level.
Wants funny is a buddy of mine just bought a leveling kit with all kinds of gadgetry. ( I won't burst his bubble)
LOL. If he shoots more than 200 yards its a long way. He's mainly a hunter. Nothing wrong with that.
Theres a big difference between what and how he shoots vs what I've been trying to do, Hit these fricken plates at 300 to 900 yards. Whats neat is i keep picking up little did bits here and seems like every time I apply them I shoot a little better.
I have a scope level on my scope tube and it seems I always have to jockey the rifle before I shoot to get the scope level to indicate level.
Tells me I'll have to rotate my scope some to the plumb line when I have a good comfortable mount of the gun in my shoulder pocket ,then re- level the scope level.
Wants funny is a buddy of mine just bought a leveling kit with all kinds of gadgetry. ( I won't burst his bubble)
LOL. If he shoots more than 200 yards its a long way. He's mainly a hunter. Nothing wrong with that.
Theres a big difference between what and how he shoots vs what I've been trying to do, Hit these fricken plates at 300 to 900 yards. Whats neat is i keep picking up little did bits here and seems like every time I apply them I shoot a little better.
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