Best way to level a scope

[Bigragu]

Suggested reading on the Wheeler kit:

Wheeler Engineering Scope leveling kit

Hey guys! I've been eyeing up the Wheeler leveling kit for quite some time so, I decided to make a video review on it and some other tools from Wheeler. (The video's down at the bottom if you want to skip right to it.) I'll share some quick thoughts on each tool set here but, for more details...

www.airgunnation.com

Like many scope mounting jigs, it relies on a variety of assumptions about the perfectness of the gun, mounts, and scope that may or may not be true.

Jason I know you’re a big fan of the popular mirror reflection method, and I’ll be honest with you and all on here, I not only struggled trying that but I’m having a hard time visualizing what’s been explained a million times on the procedure.

When I did try it here were my struggle points-
1. Distance to mirror without sun reflecting off of mirror.
2. Then do it inside, yes? Well I don’t have a long enough distance from a table to a mirror.
3. FFP scopes with this method for some reason was the final wall I hit, where I said fook eeet and used my traditional method. I did verify any cant afterwards by shooting onto a perfectly square and lines perfectly perpendicular, target grid to see if you/down turret adjustments would start going sideways but no, my tracking held true.

So, as I’m not a quitter until I’ve tried it and tried it correctly, is there a video or pictorial procedure that shows the mirror method out there? This is for sure a procedure where me being a 100% visual learner, will need to see the steps.

The last thing i struggled with while looking thru the scope at my reflection was, truly seeing the 12:00 position on the bore, and being in that position for as long as I did with a fused neck, well, let’s just say I was sore for a day.

Oh!! Make sure and rope up your bathrobe well, too, and don’t spread legs, when using the mirror method. I had a WTF moment when I put my eye to the scope

 

[whyzee]

I may be able to help Brother.
I too felt as if I needed a
Mentor to show me how to do the mirror method, but I recently accomplished it
Myself.
I performed the method indoors, using the longest distance I had, which was down the hallway.
Setup airgun on a stand/vice on a table. I used a Caldwell Stinger on an MTM folding table.
Next measure from floor to barrel at the muzzle. Using this measurement, hang /place a mirror at this height down the hall and on the bedroom wall, facing back at your gun/shooting table. Go back and forth from gun to mirror, making the adjustments to the mirror to reflect back at you/gun perfectly. My mirror did not sit perfectly flat against the wall when hanging from a nail, so I had to shim it away from the wall at the bottom edge a tiny bit.
Next I placed a small dot sticker ( the ones for repairing splatterburst targets) centered right on the barrel end/thread protector.
Assume the position behind your rifle and look through your scope, adjusting the focus till you see yourself clearly in the hanging mirror, while viewing through your scope.
Now, you should be able to see your windage crosshair of your scope reticle intersect the bright orange dot on the end of your muzzle.
Make adjustments of your scope within the mounting rings as necessary so that the crosshair splits the dot in half.

Hope this helped.

 

[scotton]

The last thing i struggled with while looking thru the scope at my reflection was, truly seeing the 12:00 position on the bore, and being in that position for as long as I did with a fused neck, well, let’s just say I was sore for a day.

Just for clarity, the reticle doesn't need to be perfectly vertical. It just needs to hit the center of the bore. You could lay the gun on its side and this method still works.

We are doing two different things when we level the scope. One is getting the reticle in line with the bore. Some people use a level on the action or pic rail to accomplish this, but centering on the bore is the most accurate (in my opinion). This step involves rotating the scope until it is in line with the bore, regardless of the reticle's relationship with gravity. The scope level has no bearing on this step.

The other thing is aligning the scope level with the reticle. This is where we want to figure out when the reticle is level so that we know the bore is vertically aligned with the reticle. This is accomplished by getting the reticle level using a plumb bob, flashlight on the wall or just lining it up with a level line. Once the reticle is level, we make the scope level show as level. This can be done with the scope off of the gun, since the only thing that matters is the relationship between the reticle and the scope level. The scope level is really a reticle level, not a gun level.

So the two steps can be done in either order. I usually get the scope level set first because that's easiest to do, and then the level is locked in place and doesn't need to be moved again, even if moving the scope to a different gun.

Then I put the scope on the gun and use the mirror method to align the reticle to the bore by moving the scope.

I hope this makes sense, sorry for being a little long winded.

 

[Airgun-hobbyist]

For the mirror method, I put a piece of fiber optic cable into the breech/bore so it glows to make it easier to see in the mirror. Also, if you are doing this inside (depending on the room that you have), the scope has to have a short 10 yard parallax adjustment to focus down enough to see in the mirror clearly.

 

[Airgun-hobbyist]

I've been thinking that there may be another method of "shooting in" the true relationship of the scope with bore, (provided the scope is held truly vertical), that would work similar to "walk back tuning" a bow and arrow setup. Starting from a zero point of say 20 yards, shoot a group, then move back to 30 yards, using the same aim point on target and zero hold, shoot another group which will hit lower. Then go out to 40 and 50 yards and up into 10 yards doing the same. If the bore is in line with the scope all the groups will be vertical. If not, they will be canted in one direction. The scope will need to be rotated in the rings accordingly if it is off.

 

[bigHUN]

Back in time I wanted to buy this bore-to-scope-alignement tool from Brownell/EXD/ and many more to name, but no stock or crazy costs or shipping charges, finally ended up 3d printing it myself.

Works great, but next time if I would make/print a new one, I would make the slot at least 3x wider, so I can comfortably use a flashlight instead of looking through the scope and having a crick in the neck for a week..

 

[Headshots]

Put your gun in a vice and level the bottom half of your rings with a level. Put your scope on and level the elevation turret. Or level the rifle and hang a plum bob and match your vertical line to it.

I just eyeball mine and haven't had any issues.

 

[scotton]

Back in time I wanted to buy this bore-to-scope-alignement tool from Brownell/EXD/ and many more to name, but no stock or crazy costs or shipping charges, finally ended up 3d printing it myself.

View attachment 340168

View attachment 340169

View attachment 340170

Works great, but next time if I would make/print a new one, I would make the slot at least 3x wider, so I can comfortably use a flashlight instead of looking through the scope and having a crick in the neck for a week..

View attachment 340171

Do you have an stl for this? I would love to print one and play around with it.

 

[bigHUN]

Do you have an stl for this? I would love to print one and play around with it.

This was a first prototype, the tolerances were designed for a resin printer which is way more precise in XYZ vs filament printing.
If you can wait 2-3 days I will change the design and make some "window" loarger opening so we shall be able to use a flashlight as well in same setup ones to tool is mounted. Right now the slot is narrow for a flashlight, also give me the bubble length so I can thread the holes for mounting.

 

[HoosierGunner]

Most scope mounting strategies that involve the use of levels or wedges are making a variety of assumptions about the perfectness of critical features of the gun, scope, and mounts. Granted, frequently these items are close enough that you’ll get a better result than by just eyeballing it, but it’s frustrating to see expensive “professional” jigs that will leave you with an improperly aligned scope if something isn’t perfect. For example, it’s not uncommon for the reticle to be rotated a couple of degrees relative to the turret caps, or for 3/8mm or 11mm rings to be offset slightly, or a variety of other issues.

What matters is that the reticle is aligned to the bore. The good news is it can be done with no special tools. All you need is a mirror.

But first let's establish that the requirements to eliminate cant error are:

1. Align the scope's reticle with the rifle's barrel.
2. Hold the reticle level when shooting.

Item 1 deals with scope cant…i.e. mounting the scope incorrectly.

Item 2 deals with gun cant…i.e. holding the gun incorrectly.

To correctly align the scope to the barrel, set up a mirror at a distance of, say, 5 yards and set your AO to 10 yards. Look through the scope at your reflection in the mirror. Twist the scope in the mounts until the vertical bar of the reticle simultaneously bisects both the muzzle and objective bell. Then lock it down. At this point you have eliminated scope cant (item 1). If it's hard to see your muzzle, add a little dot of White Out or take a dot from a hole punch and tape it to the muzzle with clear tape.

Now to eliminate rifle cant, install and use a level. View a known good plumb line (e.g. hanging string) through the scope and orient the rifle so it precisely aligns to it. Now affix your level so it shows level. From now on when you're shooting, hold the rifle so it shows level and you can be sure you've eliminated both potential sources of cant error.

By the way, don't buy a level that attaches to the scope rail. There is no guarantee it will show level. Instead, get one that attaches to the scope tube so you can rotate it and lock it down where it shows the proper level.

One caveat, if your rail mounted level is digital and can be zero'd, you should be able to use it vs. ring level. Ex. LRA Send-It. Great post!!!

 

[bigHUN]

OK, I 3d printed this tool yesterday (rev.2) and just finished setting up a scope on the Leshiy2.
Barrel to scope alignment + projected reticle (with a flashlight) + scope bubble tune in a single setup.
I know that the scope need to be shot anyway for 10 and 100 meters to hit a same vertical, so I did not wanted to spent bigger bucks on those (westhunter adjustable from amazon decent cheap).
Pretty much 5 minutes exercise, and next is a gun range to do the alignement (walk back tune) 10 to 100 to hit a same vertical, pretty much could be done with 10 shots max.

 

[EliteAirCustoms]

Put your rifle in a gun cleaning vise or even a bipod and level the block with small bubble level across the rails or rings. Then carefully use the bubble level to level the top turret and tighten to 18lb

 

[nervoustrig]

Put your rifle in a gun cleaning vise or even a bipod and level the block with small bubble level across the rails or rings. Then carefully use the bubble level to level the top turret and tighten to 18lb

That is the method I learned from deer hunters when I was growing up. In this part of the country, the abundant vegetation means there will seldom be a shot longer than about 200 yards. Given the relatively small amount of drop from a powderburner at that distance plus the large kill zone of a deer, that’s good enough. More than good enough.

However it is a method subject to over a half dozen sources of error given in reply 17. These errors affect a pellet much sooner. For example the popular 18.1gr JSB pellet will have as much cant error at 100 yards as a 30-06 will have at 400 yards. Whereas at shorter distances it may not be meaningful, depending on the kind of precision you want or need. At 50 yards, a 2° cant angle will produce about 0.2" of lateral error for the same 18.1gr pellet. At 100 yards, the error grows to over 1 inch (i.e. a doubling of distance produces over 5x as much error).

 

[EliteAirCustoms]

That's very informative information. Thanks you. I'm learning new stuff all the time. I'm new to AGN. Loving all the valuable information. Thanks

 

[Scotchmo]

nervoustrig,

GUN_cant_error vs SCOPE_cant_error.

Those approximate errors that you stated (0.2” at 50yds and 1.0” at 100yds) are what we get if the gun is canted when breaking the shot (or the bubble level is off by 2°).

poi error = (TAN 2°) x drop

drop is the gravity induced deviation from the bore line.

That can happen even if the scope reticle is perfectly aligned with the bore.

In the instance where instead, the scope is canted 2° in relation to the bore, yet held perfectly square to gravity, there are still errors, though smaller than you stated.

With 2° scope cant (as opposed to gun cant), it’s this:

poi error = (TAN 2°) x hold_over

Click adjustment has the same affect as hold over when the scope is canted.

Strictly scope cant error results when the scope reticle is not aligned with the bore, yet it was still sighted in correctly and held with the reticle vertical when shooting.

 

[AirShot]

Wow....sure wish I was in the scope leveling device business, more contraptions out there than I could ever count. A simple piece of modeling clay and a few bubble levels is all I have used for over 35 years. Kinda cool to see what all people go thru and how much money they spend to achieve the same results.. Not being critical here, just find it interesting....

 

[nervoustrig]

Scott, thank you for pointing that out. I try to be mindful of the distinction between gun cant and scope cant but I was accidentally conflating them. Glad we have you here to steer it back .

 

[stanginthe11s]

trig, when you set up that way do you still have to adj. windage when you sight in?

 

[nervoustrig]

Yes, other than pure luck, there will always be some windage adjustment necessary to get zeroed. Rather, the goal is that once it’s zeroed, any holdover (or holdunder) will produce shots that land predictably somewhere along the vertical bar of the reticle, not somewhere off to the side.

 

[Richieg]

I do mine indoors so I don’t have to deal with the plumbob moving in the wind.

I have tried and used several methods. From the tapered shims you use, to the wheeler scope levels you attach to the barrel and action.BOTH these methods count on the reticle being aligned with the scope turret tops or the base of the scope, which isn't always the case.
My method for awhile now has been to level the action, look at the plumbob hanging at at least 25 yards away and rotate the scope until it aligns with the plumbob. For those who used the levels or shims...try the plumb bob method after you get it set up and see if your reticle, with the action level, will align with the plumbob. You may be surprised it's off.