Rifle Scopes Tricks to mount optic perfectly horizontal?

Re: Tricks to mount optic perfectly horizontal?

I found this out by accident. Take a piece of string, tie around a 1lb. weight...melon...something with some weight to it and then hang it from something, then point the scope at it and just line the vertical line of your reticle with the string...or just have GAP build you a whole new rifle...that works too.
 
Re: Tricks to mount optic perfectly horizontal?

You guys with all these crazy ideas, just listen to Frank and use feeler gauges its 99.9% accurate and easy. Ive been doing a variation of the same thing, using machined aluminum blocks i made that fit between the base and scope bottom.
 
Re: Tricks to mount optic perfectly horizontal?

I use a machinist's level made by Starrett to first level my rifle and then clamp it in my workbench vise.

I then use the same level to get the elevation turret perfectly vertical.

I use this method on long-range setups where I'm more concerned about dialed elevation moving in a vertical line.

If I'm mounting a scope which will be used for holdovers, etc. and am more concerned about accurate vertical tracking of the holdovers, then I plumb the reticle itself.

I agree that reticles should be plumbed to the erector in a quality scope, but often times they are not.
 
Re: Tricks to mount optic perfectly horizontal?

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Originally posted by coyotekid:
<span style="font-weight: bold"> I use a machinist's level made by Starrett to first level my rifle and then clamp it in my workbench vise.

I then use the same level to get the elevation turret perfectly vertical.

I use this method on long-range setups where I'm more concerned about dialed elevation moving in a vertical line.

If I'm mounting a scope which will be used for holdovers, etc. and am more concerned about accurate vertical tracking of the holdovers, then I plumb the reticle itself.

I agree that reticles should be plumbed to the erector in a quality scope, but often times they are not. </span></div></div>This is the method I also use, but I am using a digital level.
 
Re: Tricks to mount optic perfectly horizontal?

I leveled mine by tightening the rings enough to allow movement of the scope, then holding the rifle by the butt, look through the scope. You can just make out the crosshairs. I then make sure the verticle crosshair goes down the centerline of the rifle. Check with a small bubble level. Then finish tightening the rings. Seems to work well for me.
 
Re: Tricks to mount optic perfectly horizontal?

I may be missing something here, (likely), but I use a Bushnell collimator to line up crosshairs.

I have a lot of machinist tools, but haven't worried about the level of my base or scope. I generally install base and torque the mounting screws to 15 inch lbs, and then install the bottom ring half, torqued to 65 in lbs.

Putting the scope which has been returned to median points into the rings and lightly tightening the top ring half, I tighten the outer screws and then the inners; paying attention to keeping the crosshair dead-on with the collimator.

It does not take much unbalanced pressure to move the reticle off the collimator grid.

Admittedly, I am not using a custom ground spud to center the collimator, this maybe puts me off, but... Compared to how easy it is to over tighten one screw and shift the whole reticle, I think keeping the reticle perfectly centered on the collimator grid is critical.

A collimator can be used for many other purposes besides mounting scopes; checking the movement tracking, or keeping track of zero positioning when the scope is mounted on another rifle, or remounted on the original rifle.

If you really want an awakening; try testing the slot widths on your scope base with a gage block. Even on the best/most expensive mount, some will be off. Then take an 8" caliper and measure the distances from each slot on each side; slot by slot.

I have never epoxy bedded a scope base, but that is one way of really "being sure". When you get into shimming a base or ring, I think you wind up negating some other factors that you want working for you, like the fit of the base to the receiver contour. Shims will work, but they are not an elegant solution.

Something else you may be overlooking, the forward most base screw can, if left too long, impact your barrel threads and have detrimental effect on your shooting equation. So, be sure your base's forward mount screw doesn't impact your barrel.

I am sure the plumb-bob idea is a good one, I use the collimator to track the movement in all directions. If anything is off, it is readily apparent.

I have not tested/measured the other variables in my scope mount setup. I am sure if there is slop in the slot spacing and width, there must be variances in the height of the base and then in the corresponding surfaces of the scope rings. Who knows? Maybe we need to lap/grind all mating surfaces to be sure? If I was shooting benchrest, I might look into this further.

In the real world, receivers are not perfectly round, base mount holes are not perfect because of variances, and holes might not even be in-line. Many rifles that aren't "perfect" will shoot with those that are.

If I wasn't into switchbarreling, I think I would bed my scope bases. A collimator really makes setting your scope up a snap.
 
Re: Tricks to mount optic perfectly horizontal?

This thread got me wondering....

I mounted a new-to-me Mk4 today, on a Badger Ord 20moa base, in Badger .883 Normal rings. I used the Bushnell collimator.

Did some tracking tests, the scope movements are fine.

Later, I got out a Starret gage block set and Craftsman feeler gage set. Oiling up a variety of blocks to gage the distance between the rail top and the turret housing bottom which looks pretty flat, but might NOT be ground perfectly flat, (oh well...).

Anyway, I loosened the ring screws after a number of tests showed that a .132 and .050 block combined with a .015 feeler leaf was just about right. With the collimator still in the barrel from this afternoon, I found that a block of .1835" would perfectly support the turret housing. I tightened up the screws to about 8 or 10 in lbs by feel and found that there was no movement at all on the collimator.

I had never thought of setting the scope with a gage!

I have seen some high dollar bases that were out of spec, (corrected to read) 'that should NOT have been'. Yet, if you check your base and ring dimensions, and chose a uniform spacing for your scope rings, a custom ground gage block would really do the trick; at least as regards setting your scope perfectly level on your base.
 
Re: Tricks to mount optic perfectly horizontal?

How about we get Marty to supply a precision ground clamp-on block for each different height ring set and then use Frank's feeler gage trick. A little more expensive probably but fewer feelers/moving parts.

As for me, so far it's been a USO bubble level clamped to my BO bases with a bright orange plumb line hung at 100 yds on a black target board. Not perfect but close. Hard to tell exactly when the bubble is level and I've had several bubble levels that weren't actually level. Of course I sent them back to USO and they replaced them.

Another idea would be to have the scope nad ring makers provide some sort of indexing point or flat on the scope specifically for this issue. Hard to screw up one of the Leupold Gilmore red dots that are hexagonal and have matching rings.
 
Re: Tricks to mount optic perfectly horizontal?

While I won't use one for boresighting, naked eye works better in most cases, the Collimator should be the perfect tool to get the x-hairs plumb to the bore. Might consider picking one up for that purpose.
 
Re: Tricks to mount optic perfectly horizontal?

I use the most expensive optical devices known to man; and, although mine are 57 years old, they still work to square up my scopes perfectly, as far as I can see, forgive the pun. Od course, I'm talking about my eyeballs.
 
Re: Tricks to mount optic perfectly horizontal?

Here is the best way to be sure that you're taking into account all variables.

Take a large target stand and set it up at 100 yards or so. Take a level and draw a vertical line on this sheet of paper. Now make a tick mark at the bottom of the sheet.

Ok now take your rifle and shoot at the plus made by the tick mark at the bottom of your perfectly vertical line. You should hit the center of this plus dead on. (if you don't then zero your rifle).

Ok now you're zeroed. Crank your scope up a good 20+ MOA. Now hold dead nuts on that same tick mark intersection. If your bullet hits within 1 bullet width of the vertical line then your scope is level. If its to the right then you need to spin your scope counter clockwise. If you hit to the left you need to spin clockwise. I've found that drawing a line between your ring and scope tube can give you a good point of reference in order to help you see the adjustments you've made.

If you take a large sheet of paper and test this over a large amount of travel and you pass this test thats all that really matters. The main thing is that you have to be sure that you keep the gun what you consider level when you do this. A bubble level or something like that mounted to your rail can help you keep this as consist ant as possible.
 
Re: Tricks to mount optic perfectly horizontal?

I went to the hardware store and bought a line level and put in on top of my elevation turret. Made sure that the surface was level first and put the bubble in the middle of the level. I think it worked fine. And was only 2 bucks.
 
Re: Tricks to mount optic perfectly horizontal?

Been using the feeler gauge method for a while, works well. One easy way to check the erector tracking is with a Leupold boresighter magnetically attached to the crown.

Tweak the boresighter until the vertical of the reticle and the boresighter are parallel and then wind the elevation up and down, it should track. If it doesn't, iterate mount and boresighter rotation until tracking and boresighter vertical are parallel. Yeah, it's a seriously tedious pita.

This assumes crown is square to bore but then it usually is pretty dang close on a well built rifle ime and isn't all that important given how the boresighter works. Gets reasonably close before checking at the range with a plumb line I think.

I'm pretty sure a shooter's aiming cant is going to swamp erector tracking cant error over range though. But I ain't no expert, that's for sure.
 
Re: Tricks to mount optic perfectly horizontal?

Midway has a scope mounting kit which includes a sprit level and lapping kit to mount your scope. Combine that with a laser bore sighter and torque wrenches and you'll do such a great job, you will think you are an engineer!
 
Re: Tricks to mount optic perfectly horizontal?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dino1</div><div class="ubbcode-body">so I ust be an idiot, I'm not really sure how the feeler guage thing works? How about some ms paint to clue me in??? </div></div>

You just use a stack of feeler gauges under the knob housing. It usually is flat on the bottom. You make sure the bottom of the knob housing is parallel to the scope base by using a stack of feeler gauges.
 
Re: Tricks to mount optic perfectly horizontal?

The link:

http://www.snipershide.com/modules.php?name=Content&pa=showpage&pid=25

Pictures and everything...
nfmount07.jpg

nfmount08.jpg

nfmount09.jpg

nfmount10.jpg
 
Re: Tricks to mount optic perfectly horizontal?

Coyote kid nailed back a few posts over a year ago.

If the turrets and mechanical parts aren't level, your adjustments will be off. For the guns I shoot long range I am much more concerned with the turret adjusting vertical correctly than the reticle being perfect. I use 2 line levels from the hardware store. The feeler gauge method works great also. The levels almost needs a vise to hold the gun square as you can't always get the level on the base while the scope is mounted.
 
Re: Tricks to mount optic perfectly horizontal?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tactical</div><div class="ubbcode-body">Put level on scope base for side to side level of rifle. Put level on elevation turret top to level errector. That way errector moves straight up and down with bore. Thats it. </div></div>

That's what I do. I just level up to my rail mounted bubble, and level across the elevation turret. If my scope ain't scuare to my rail mounted level and I use the rail mounted level while shooting I'd be SOL........
 
Re: Tricks to mount optic perfectly horizontal?

If your crosshairs are not canted and are tracking correctly, is not the idea to line the vertical exactly with the bore of the rifle?
I use a laser bore sighter with a lens that breaks the beam into a linear projection. I rotate the scope and bore sighter until both the vertical and the projected line overlap. I then prove this at the range with the plumb line method.
There have been a number of systems through the years that have been used to align the vertical with the bore.
 
Re: Tricks to mount optic perfectly horizontal?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: s.i.t.</div><div class="ubbcode-body">wow lowlight, are things over there that expensive? i bought a set of feeler gadges the other day and only paid 6 bucks for them</div></div>

Last set I bought were $7, so my price was off, I dont recall where we got them but you can find them cheaper for sure... two sets should be way below $20.
 
Re: Tricks to mount optic perfectly horizontal?

SWFA sells the Bsquare and the CTK rifle levels.
T1006.jpg


I have the $20 B-square rifle level.
SWFA's pic is upside down.
B square does not have a pic.
What? for $20 they should have a pic?
For $80 something US Optics will sell one that folds.
Mine is on a varmint rifle, that rifle never goes in a drag bag.

I look at buildings through the scope and get the vertical part of the reticle parallel with the vertical part of buildings.
 
Re: Tricks to mount optic perfectly horizontal?

Might be able to combine mounting and proving into a simple (relatively) procedure. Take your plumb line to the range. Make a vertical line on target using plumb line. Mark a horizontal line across the vertical. Place your rifle in a rest. Remove bolt and center bore on vertical. Adjust bore and vertical crosshair until they are lined up with vertical on target. Tighten screws and double check. Fire on target. Run up the elevation while lining up on target to check if elevation is in line with vertical crosshair.
Mount, sight in, and prove in one process using just a target and plumb line.
Does this make sense?
 
Re: Tricks to mount optic perfectly horizontal?

Interesting....I used a Collimator.

I will go get some feller gages monday and see how things look that way.

Has anyone found themself really off after useing a Collimator?

Also has anyone ever found they had to get there reciever re-taped to get the base into alignment?
 
Re: Tricks to mount optic perfectly horizontal?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Firsthruthedoor</div><div class="ubbcode-body">Again, I think the critical point is that your vertical has to be in line with the center of your bore. </div></div>

Azimuthal error can be zeroed with windage but offset can't be corrected by scope adjustment or mounting other than by the 'smith getting the mounting rail inline and bedded for zero twist, cant, and offset - a fine trick. And one that works right up until the scope gets mounted and the rifle fired.

It takes a lot of offset to add error to the ideal drop numbers so it's not really a worry although I don't think you'd find an installed rail or mounting system that exhibited only offset.

The only meaningful 'calibration' is getting the erector travel to be parallel to gravity, basically. And then you can start adding in all the gazillion variables that swamp all the theoretical numbers the farther out you're shooting.

Just remember it's impossible to keep the erector travel axis perfectly orthogonal to the horizontal while holding for fire. If'n ya' don't believe me set a quality machinist's level transverse on the rear end rail of an AR and watch that bubble dance back and forth as you try and hold perfectly vertical by trying to center the bubble and hold it there. A bit more instructive than the typical rifle-specific bubble levels given the greater sensitivity.

Be consistent, gather useable data, know your dope. Much more important than worrying about tweaking out the last arc-second of error in plumb when mounting the scope. IMH, and limited, opinion of course. Like I've said before I'm pretty sure sighting cant error will always be greater than installed erector travel cant error but is only noticeable over very long distances, assuming a competent rifleman behind the scope. YMMV.
 
Re: Tricks to mount optic perfectly horizontal?

Mounted three scopes today. Mainly swapping them around. I leveled the bases using a string level, adjusting bipod legs until the rifle was level according to the level and base; then mounted scope and aligned the horizontal wire with the siding of the garage across the street. I've installed enough siding to know the installers level the siding pretty exact.

Greg
 
Re: Tricks to mount optic perfectly horizontal?

justpete

You are right. Having the linear center of the bore coplanar with the linear center of the scope is ideal and not easy to accomplish in the real world. Having that plane aligned with the pull of gravity is even more difficult to accomplish.
I often thought that having the fate of an extreme range target dependent on these factors and judging range and wind was as much a matter of luck and fate as skill. First shot cold barrel. Ya pays ya penny and ya takes ya chances. Do the gods favor you?
 
Re: Tricks to mount optic perfectly horizontal?

I guess it's cheating but I use a t2000 lieca theodolite. It's got a 10 second level
in 2mm. I always wonder (and have asked) how accurate are the levels being used?
My transit reads to 5 minutes, the t2000 to .5 seconds, huge difference in the level
required to set it up. A half second is 1/400" in 100 ft. So centering the bore below
the scope is dead on. Once the bore is straight below the scope center the rest is
easy, I can set up behind the scope and look through it, but it is quicker to use a
plumb bob. I like the idea of running the erector up and down the string line. I have
at least one scope that I think is going to be off quite a bit.
 
Re: Tricks to mount optic perfectly horizontal?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Torfinn</div><div class="ubbcode-body">I did my last one with a deck of cards and plumb line. </div></div>
Thanks for this post. That is a great idea.
 
Re: Tricks to mount optic perfectly horizontal?

Hell yeah, to the feeler gauge. In fact, that's exactly what I said, when I got done with this simple little trick.

"Hell, yeah."

Seriously, this is crazy easy to do anywhere. My feeler gauges cost $3, and it's perfect because it mechanically forces the scope level with your rail, with no complicated leveling set-ups.

And I learned it right here on Sniper's Hide. Thanks Lowlight.

Nik
 
Re: Tricks to mount optic perfectly horizontal?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: SWFA</div><div class="ubbcode-body">Using the top of a ring won't work.....

2004-10-23_144858_L1010503.JPG


.....because, how do you know the top of the ring is level to the reciever of the rifle?

What if you tightened one side of the ring more than the other? What if you reciever is not level?

I guess we could what-if it to death....huh?

Doing any and or all of these methods is all we can do. </div></div>

Where can I get one of those?
 
Re: Tricks to mount optic perfectly horizontal?

after reading thru some of the replies in this thread, i thought id share my very simple method that seems to work a treat for me, and so much simpler than some of the methods previously listed...

1. I place a small spirit level across the picatinny rail of the rifle and get the rifle level on a bench rest or using the bipod or bags whatever and aiming at a tall vertical building/structure in the distance out the window/shed/door etc. Tall Buildings are great coz they provide a huge plumb line at distance.

2. then i mount the scope on the rifle with the rings just tight enough so that i can make adjustments and get it close where i want it by eye for starters.

3. Now get behind the rifle and simply line up the vertical line of the reticle with a vertical edge of the building whilst looking thru the scope, move the scope until the both of your references are flush and therefore aligned plumb.

4. tighten the scope rings and your done.
smile.gif
You can then check the tracking of the scope as a bonus while your here...

5. to check the tracking, simply wind up the elevation whilst the reticle is aimed at the edge of the building about half way up. After you dial 20-40MOA up or down, if the reticle is still aimed dead on the edge of the building (although much higher/lower now), and hasnt drifted off your plumb edge, then it must be tracking plumb yeah?

Too easy.


 
Re: Tricks to mount optic perfectly horizontal?

After mounting, I check alignment.

I start by levelling the target, which is relatively easily done by looking back and aligning the top edge of the target with the roof peak of our covered firing line.

I then take a shot at a small aimpoint near the bottom of the target, then another with 10" of elevation, another with 20" of elevation, etc. until I run out of target height.

If the scope is properly leveled, a plumb line hung from the top impact should pass though the others. The proof of the mounting is in the shooting.

Greg
 
Re: Tricks to mount optic perfectly horizontal?

hardware stores have string levels for sale relatively cheaply. Their bases are level with their bubbles, and they easily fit a couple in a pocket.

Greg
 
Re: Tricks to mount optic perfectly horizontal?

as an addition, ive found that a scope rarely needs to be mounted level, usually the reticle is not level with the scope body, therefore you need to mount the scope so that it TRACKS plumb and level regarless of its physical orientation. So placing levels on the scope body is ususally a waste of time...
 
Re: Tricks to mount optic perfectly horizontal?

I put a level on the rail, level the rail / rifle, thenI have a 36" level screwed to a fence post in the back yard that I align the verticle on the reticle with.

This is just extra feel good medicine for me though.
 
Re: Tricks to mount optic perfectly horizontal?

Potentially dumb question fellas but I dont know the answer, so here it is.

With the anti-cant scope level devices... Can you actually even see the normal ring versions while behind the scope taking a sight picture?

acd-black.gif


Or is it better to get the side mounted ones out of the way of flip covers / lens rings etc.

BS-T1005.jpg


What are your thoughts lads?
 
Re: Tricks to mount optic perfectly horizontal?

You can see the tube mount type with both eyes open, assuming that you lens cap is not in the way. I personally prefer the USO rail mount type. They are easier to see and I like that they are on the rail as opposed to the scope.

Both work, you just have to play around with the set up to get it right.

Either way you have to have both eyes open to see them.
 
Re: Tricks to mount optic perfectly horizontal?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 96C</div><div class="ubbcode-body">Potentially dumb question fellas but I dont know the answer, so here it is.

With the anti-cant scope level devices... Can you actually even see the normal ring versions while behind the scope taking a sight picture?

acd-black.gif


Or is it better to get the side mounted ones out of the way of flip covers / lens rings etc.

BS-T1005.jpg


What are your thoughts lads? </div></div>


Is there a scope out there that has the level (bubble) inside it?? So you can see it while taking aim?