Good Scope Mounting Tools

bruce_ventura

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Make sure to get a Wheeler FAT Wrench. Also, get T10 and T15 Xcelite drivers. They will come in very handy.
Good suggestion. I've found that there is enough space inside the FAT wrench box to put a small hex driver, and still get the lid to close. Then it's just a matter of adding a few extra bits that you use frequently (T10, T15, 5/32 Allen, 3 mm Allen, etc.). Then you have a screw driver and a torque wrench, each with the correct bit.

Although the Wheeler FAT Wrench comes with nine bits, they don't include either the T10 or the 3 mm Allen bits, which are commonly found on Burris, Millet and other rings. The 3 mm Allen bit is not even sold by Wheeler, which is mystery to me.

That's why HighPowerOptics includes the T10 and 3 mm Allen bits with the Wheeler FAT Wrench (total of eleven bits).
HPO/Wheeler FAT Torque Wrench 553-556 w/ 3mm and T10 Torx bits
 

bruce_ventura

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...One could be level with the rifle in the field only to have then introduced the opposite scope cant to the equation. Seems strange to invest $1-$3000 on a scope and another $3-$5000 on a custom rifle and precision rings/bases etc. only to have a undetectable 2-10 MOA rifle scope missalignment causing you grief...
Gunner, I suppose this would happen if you located the anti-cant indicator on the rail, instead of the scope tube as Woods' photo shows. Attaching the anti-cant indicator to the scope tube is the preferred method for the following reasons.

First, I've calculated the alignment errors and the resulting scope cant sensitivity many times, and I've confirmed those calculations in live fire experiments. Here is what I've found. If the scope cant is removed but the scope vertical turret axis is not aligned to pass through the bore, the scope optical axis and the bore axis will not be parallel in the horizontal plane. The two axes will cross at the zero range. There will be a small but measurable horizontal offset in the point of aim that increases with distance from the zero range.

Horizontal offsets in the scope tube relative to the rifle bore can occur due for a variety of reasons. The most common source is left-right asymmetry in the ring attachment to the base, but base installation, height of the rings and barrel alignment to the receiver can also be factors.

Using the EXD and HighPowerOptics Reticle Alignment Tools essentially eliminates this source of aiming error, but can result in the scope tube being canted when the rail is level (not canted). In this case, attaching the anti-cant indicator to the rail will cause a scope cant.

Second, if the anti-cant indicator is attached to the scope tube the indicator can easily be rotated the required number of degrees (for that bullet and MV) to compensate for spin drift. Doing the same thing with the anti-cant indicator attached to the rail is more difficult because it requires the scope to be precisely rotated in the rings.

None of these alignment criteria are sensitive 2-10 MOA of alignment error. Holding scope cant error to within 30 MOA (0.5 degree) is usually adequate for long-range shooting. I say "usually", because it really depends on the caliber (the point of aim error due to scope cant is proportional to time of flight). I assume we're talking about flat-shooting calibers with adequate bullet energy at long range.

Also, the spirit levels found in scope alignment tools and anti-cant indicators have a sensitivity of 30 MOA per mm of bubble travel. In my experience, an error of 10 MOA cannot be measured reliably without a machinists level, and no one I know uses a machinists level in the field to remove scope cant.
 

cummins cowboy

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I developed a similar tool that is sold by HighPowerOptics. The Reticle Alignment Tool performs the same function as the EXD tool, and it includes a very accurate spirit level for leveling the scope turret axis. Plus it sells for a lot less ($26).
Reticle Alignment Tool

so are you able to see those lines when looking through the scope and index the reticle with the lines?? if so that would be an advantage over the EXD tool, further how does this too stay against the bell of the scope??

I think what some people aren't understanding about the EXD tool is you can see through it through the slot. so you are leveling the rifle then aiming the scope at something level and leveling the crosshairs. you do all this with the EXD tool on the rifle. I personally us my neighbors back window on their house to level off of, out my back door. all is done with the EXD device on the rifle the whole time. I do that and lately I have been moving over to pic rails on all my guns, so I just level the bottom of the scope to the pic rail with an allen wrench
 

phorwath

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Using the EXD and HighPowerOptics Reticle Alignment Tools essentially eliminates this source of aiming error, but can result in the scope tube being canted when the rail is level (not canted). In this case, attaching the anti-cant indicator to the rail will cause a scope cant.
I mount my anti-cant indicator to the rail, but I place marks on the bubble level tube to ensure the bore, scope tube, and scope reticle are all plumb with the world, during the scope mounting and setup procedure. It no longer matters if my scope rail is slightly canted, as my anti-cant bubble level has marks on it to position the rifle, bore, and reticle vertical with gravity.

BTW, the marks I've placed on my anti-cant level bubble tubes don't match the marks provided by the manufacturer. So my scope rails are slightly out of alignment with the vertical bore/scope tube alignment, on three separate rifle setups.
 

bruce_ventura

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so are you able to see those lines when looking through the scope and index the reticle with the lines?? if so that would be an advantage over the EXD tool, further how does this too stay against the bell of the scope??

I think what some people aren't understanding about the EXD tool is you can see through it through the slot. so you are leveling the rifle then aiming the scope at something level and leveling the crosshairs. you do all this with the EXD tool on the rifle. I personally us my neighbors back window on their house to level off of, out my back door. all is done with the EXD device on the rifle the whole time. I do that and lately I have been moving over to pic rails on all my guns, so I just level the bottom of the scope to the pic rail with an allen wrench
Lining everything up the way you describe is too complicated for me. I install scopes 5-10 times each month - at the range, at the HighPowerOptics store, in my garage, on the dining room table, etc. I've found that hanging a plumb line that I can focus on through the scope takes too long to set up. Plus, I'm not as interested in leveling the reticle as getting the turret axis plumb to the earth. I've found that reticle misalignment relative to the turret axes can be 1-2 degrees. It's not common, but it happens enough that I always align the turret axis instead, which is what really matters when dialing elevation for long range.

The Reticle Alignment Tool is much simpler in design than the EXD tool, and it includes long, flat edges and an accurate spirit level so that it can be used like a good carpenter's level to level the scope and align an anti-cant indicator (the EXD tool is too narrow and top heavy to use as a carpenter's level). Plus, the Reticle Alignment Tool costs less.

The lines on the Reticle Alignment Tool are for centering the scope objective on the tool. The lines are viewed from the outside of the scope, not through the scope. The tool has a strip of double-stick tape that allows it to stick to the scope objective once it is centered. Then the rifle and tool are rotated together until the spirit level on the tool is level. I perform this step with the rifle in a vise so that the rifle and tool don't rotate after I get them level.

Finally, the scope is rotated in the rings until the turret axis is level. I simply remove the Reticle Alignment Tool from the front of the scope and place it inverted on the elevation turret. Sometimes I hold the tool along a flat side of the turret housing. Other times I hold a flat steel ruler along the bottom of the scope tube housing and lay the inverted Reticle Alignment Tool on the ruler. I'm simply trying to locate a mechanical reference surface on the scope that is parallel/perpendicular to the turret axes.

The Reticle Alignment Tool is a machined part, not stamped or injection molded. The edges are square and the spirit level is manually aligned on a surface plate when the tool is assembled. The spirit level is within +/-15 MOA of being parallel or perpendicular to each of the four edges of the tool.
 

gunner69

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Perfectly said and all the boxes checked

1. Scope centerline and bore centerline aligned vertically
2. Reticle adjusted to distant horizontal or vertical object
3. Anti-cant device installed to duplicate at bench or in field

gunner, first you say "don't bother with that tool" and now you say "your's is a nice tool worth the money". Have you finally begun to understand how the tool is used?

And you have YET to explain or describe YOUR method, only redefine the problem several times (which we all have known from the beginning)

So please explain to us "a more precise method is required". And we all also know about the field method of cranking elevation and looking for vertical POI's, but we are talking about a method for MOUNTING a scope
Woods - Fair points and questions. First, I must apologize to the thread. Please pardon my etiquette - I reread my first post on the matter regarding the tool in question and I was a bit harsh in how I put it. All of these tools certainly are helpful but for the kind of precision that many on this board strive for - 1000 yards and longer, more precision is necessary. 30 MOA cant work at those ranges . Quickly for perspective, for years I was one of the guys I describe trying to solve my ultra long range issues with load development till I saw something at a range in Texas that some benchrest guys were using (I hunt and shoot tactical/FClass). It made complete sense and it was a complete game changer for how my rifles performed once I got one. I decided instead of explaining, I would show you a quick video I did this afternoon using a rifle that I haven't held it 5 years. Also just a warning, my video skills are subpar at best as is my ability to plainly explain my points but hopefully this short video will be helpful. Again I am only trying to add value and be helpful as many on this board have done for me as I improve my shooting skills and equipment. Enjoy - hopefully.

[ame=http://www.youtube.com/watch?v=sKna7iefxf8]Precise Rifle Scope Mounting - YouTube[/ame]
 

MudRunner2005

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Bruce, I wish I had bought mine from you now, I paid $50 at my local store and just the other day I had to break out the Snap-On Torx drivers because even my Wheeler 86-piece screwdriver set didn't include a T-10 torx bit for torquing my EGW rails and my DNZ 1-piece mount, so I had to purchase a T-10 longshank T-10 & T-15 for my FAT wrench.
 

bruce_ventura

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Mudrunner, I had to do the basically the same thing when I got my Wheeler FAT Wrench. At least the T10 bits are easy to find. The 3 mm Allen bits have to be ordered online. If you want one, PM me your address and I'll mail one to you.
 

bruce_ventura

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...All of these tools certainly are helpful but for the kind of precision that many on this board strive for - 1000 yards and longer, more precision is necessary. 30 MOA cant work at those ranges . Quickly for perspective, for years I was one of the guys I describe trying to solve my ultra long range issues with load development till I saw something at a range in Texas that some benchrest guys were using (I hunt and shoot tactical/FClass). It made complete sense and it was a complete game changer for how my rifles performed once I got one. I decided instead of explaining, I would show you a quick video I did this afternoon using a rifle that I haven't held it 5 years. Also just a warning, my video skills are subpar at best as is my ability to plainly explain my points but hopefully this short video will be helpful. Again I am only trying to add value and be helpful as many on this board have done for me as I improve my shooting skills and equipment. Enjoy - hopefully.
Gunner,

First, I have to say I like your covered lap pool. That must come in handy during the summers in Texas. Second, nice hardware! Your leveling vise is really nice. I’m envious. The leveling vise I put together is lame by comparison (but it breaks down into pieces small enough to fit in my portable tool box). That said, your video leaves me with more questions than answers.

I’m not clear what the purpose is of leveling the receiver races. You’re not attaching an anti-cant indicator to the receiver, so why does this even matter? Your video emphasizes the high sensitivity of the spirit level. Can you explain why that alignment step is so important?

Based on the scopes I’ve inspected, I’m confident that most scope manufacturers don’t align the reticle to the turret axis with that level of precision. What's the point of aligning the reticle to a plumb line so precisely, when getting the turret axis plumb is really the goal?

Finally, you say that 30 MOA is not precise enough for 1,000 yds and beyond. I guess that depends on the type of shooting you’re doing. For most long-range hunting calibers the aiming error for 1 degree of scope cant at 1,000 yards is only a few inches - even less at high altitude. Scope alignment to within 30 MOA has been adequate in my experience. Target shooting may be a different situation because bullets only have to be supersonic - they don’t need to carry enough energy to kill game. But if you're target shooting with a bipod, why would you be concerned about rifle cant? Doesn't the bipod hold the rifle at the same cant angle on every shot? What type of shooting are you doing that needs such highly precise reticle alignment?

Also, I’m not clear how you would reduce scope canting errors to substantially less than 30 MOA in the field. You would need a ground glass spirit level attached to the rifle, and a precisely adjustable bipod. While I wouldn’t be surprised to learn that you have them, that’s not the type of equipment most long range shooters would have on a hunting trip. Again, what’s the point of doing the alignment to 1 MOA if you can only hold to within 30 MOA (15 MOA on a really good day)?

That said, the particular rifle you are using in the video has Warne-type rings, which are split down the middle and are left-right symmetric. Assuming the rings are mounted on your Mauser action without any offset, aligning both the scope and receiver to be level will likely result in a properly aligned turret axis. That is a rare situation in my experience, because Warne rings are not very common.
 

gunner69

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Gunner,

First, I have to say I like your covered lap pool. That must come in handy during the summers in Texas. Second, nice hardware! Your leveling vise is really nice. I’m envious. The leveling vise I put together is lame by comparison (but it breaks down into pieces small enough to fit in my portable tool box). That said, your video leaves me with more questions than answers.
Yes it is hot here. It is a very nice piece of equipment. It arrives complete with ground glass ocular level, bearing surface bars and the weighted plumb line. If you want one it can be ordered by emailing [email protected]

I’m not clear what the purpose is of leveling the receiver races. You’re not attaching an anti-cant indicator to the receiver, so why does this even matter? Your video emphasizes the high sensitivity of the spirit level. Can you explain why that alignment step is so important?

Once rifle and scope are aligned you can mount an anti cant to either receiver or scope. I'll have to do another video however to demonstrate why this matters so much. It'll be later this week.

Based on the scopes I’ve inspected, I’m confident that most scope manufacturers don’t align the reticle to the turret axis with that level of precision. What's the point of aligning the reticle to a plumb line so precisely, when getting the turret axis plumb is really the goal?

Most do but non the less the reticle should be plumbed to gravity for true accurate alignment. Not turret tops level.

Finally, you say that 30 MOA is not precise enough for 1,000 yds and beyond. I guess that depends on the type of shooting you’re doing. For most long-range hunting calibers the aiming error for 1 degree of scope cant at 1,000 yards is only a few inches - even less at high altitude. Scope alignment to within 30 MOA has been adequate in my experience. Target shooting may be a different situation because bullets only have to be supersonic - they don’t need to carry enough energy to kill game. But if you're target shooting with a bipod, why would you be concerned about rifle cant? Doesn't the bipod hold the rifle at the same cant angle on every shot? What type of shooting are you doing that needs such highly precise reticle alignment?

Scope/ rifle cant is an insidious killer of accuracy which at long ranges become big misses. At 1000 yards 1 MOA = 10 inches and 1 MIL = 36 inches. Also isn't the purpose of any scope installing tool to eliminate cant to some degree? Article here worth reading Cant Errors - Long range shooting

Also, I’m not clear how you would reduce scope canting errors to substantially less than 30 MOA in the field. You would need a ground glass spirit level attached to the rifle, and a precisely adjustable bipod. While I wouldn’t be surprised to learn that you have them, that’s not the type of equipment most long range shooters would have on a hunting trip. Again, what’s the point of doing the alignment to 1 MOA if you can only hold to within 30 MOA (15 MOA on a really good day)?

If you already have cant introduced into your rifle before you get to the field you simply amplify this issue. Eliminate it from your rig then it's up to the shooter to determine taking a lever shot.

That said, the particular rifle you are using in the video has Warne-type rings, which are split down the middle and are left-right symmetric. Assuming the rings are mounted on your Mauser action without any offset, aligning both the scope and receiver to be level will likely result in a properly aligned turret axis. That is a rare situation in my experience, because Warne rings are not very common.
True
 
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gunner69

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Gunner,


Based on the scopes I’ve inspected, I’m confident that most scope manufacturers don’t align the reticle to the turret axis with that level of precision. What's the point of aligning the reticle to a plumb line so precisely, when getting the turret axis plumb is really the goal?

By the way you are correct. Leupold reticles are often 3 degrees canted. The plub line should alway reference the reticle perfectly. That is what you view aiming at the target and indicates bullet travel/gravity. Turret postion matters zero really. In theory the turrets could be mounted at any angle on the scope.
 

bruce_ventura

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Scope/ rifle cant is an insidious killer of accuracy which at long ranges become big misses. At 1000 yards 1 MOA = 10 inches and 1 MIL = 36 inches.
This is a statement about vertical and horizontal aiming error, not canting error. Yes, it is true that an aiming offset of 1 MOA produces an aiming error of 10” at 1,000 yds. I don’t see how that’s relevant to this discussion, which is about cant error.

Aiming errors due to scope canting are much smaller – by about a factor of 100. For most long range hunting calibers, the aiming error at 1,000 yds is roughly 10” for 120 MOA (or 2 degrees) of cant angle. You haven’t convinced me why anyone actually needs 1 MOA precision when aligning a scope reticle.

I’ve found that aligning the scope to within +/-15 MOA of plumb is routinely possible with a little care. This is the typical accuracy of the HPO Reticle Alignment Tool (it’s guaranteed to have an error less than +/-30 MOA). I normally don’t use any other levels or plumb lines when I install a scope and anti-cant indicator. In my experience, however, holding the cant error to +/-15 MOA in the field is not easy to do. Holding cant angle to within +/-30 MOA is a more realistic goal. For long range hunting calibers, +/-30 MOA of cant error limits the aiming error to roughly +/-3”. Of course, this error will vary depending on the caliber.

The aiming error due to not aligning the scope to the rifle bore is roughly +/-2” at 1,000 yds, although it varies a lot from one rifle to another. Using the Reticle Alignment Tool will eliminate this error.

Proper use of an anti-cant indicator will then allow an experienced shooter to achieve an aiming error of less than +/-3” at 1,000 yds (neglecting wind effects of course) without a lot of effort. Most long range shooters would be satisfied with this aiming accuracy, given that wind estimation error is usually a bigger problem. While it’s possible to get even better accuracy, I think it requires a fair amount of experience aligning scopes and shooting with an anti-cant indicator.

If you already have cant introduced into your rifle before you get to the field you simply amplify this issue. Eliminate it from your rig then it's up to the shooter to determine taking a lever shot.
Most of the shooters on this forum are mainly interested in making the long range shot, not in scope alignment methods. For them preventing canting errors in the field is the primary objective of aligning a scope. Accurate scope alignment is not the end goal for them, it is just the means to the end, and it’s really only half of the problem. How one holds the rifle to prevent canting errors in the field is the other half of the problem.

Leupold reticles are often 3 degrees canted. The plub line should alway reference the reticle perfectly. That is what you view aiming at the target and indicates bullet travel/gravity. Turret postion matters zero really. In theory the turrets could be mounted at any angle on the scope.
This is only true for holding elevation, not dialing elevation. How one deals with a misalignment between the reticle and the turret axes depends a lot on how the scope is being used. For 1,000 yd shots, I think that shooters generally prefer to dial elevation. If there is an angular misalignment between the reticle and the turret axis, and the reticle is plumb during the shot, an aiming error a will be introduced when dialing elevation, but not when holding elevation.

The reason is simple: if the turret axis is not plumb, then dialing elevation also introduces a small windage offset. This is simple geometry and many people, including myself, have confirmed this at the range.

So, my basic rule is: when dialing elevation, align the turret axis; when holding elevation, align the reticle. That way a misalignment between the reticle and the turret axis won’t cause a canting error.
 

phorwath

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So, my basic rule is: when dialing elevation, align the turret axis;
Bruce or woods,
Explain how to "align the turret axis" and confirm alignment in a straightforward, efficient manner - preferably without shooting a bunch of ammo? I've improperly presumed a scope turret would track thru its motion parallel with the reticle. But I understand how the mechanical turret movement could be misaligned with the vertical reticle... which would be quite a disappointment to me.

Could a guy secure his rifle/scope in a rifle vise, draw a long vertical/plumbed line on a piece of cardboard, line the vertical crosshair up on the line and crank the scope turret thru its up and down throws and confirm the crosshair intersection tracks up and down the line drawn on the cardboard? I've performed this procedure on all of my long range rigs in order to calculate the true value of my scope turret clicks, by measuring the distance the crosshairs move divided by the number of scope clicks per 100 yards - for a straightforward, measured determination of inches/click/100 yds.

The crosshair on my 3 long range rigs did track parallel with the plumb/vertical line I'd drawn on a large piece of cardboard at 100 yds. I was confirming my scope's click value, but in doing so, I do remember the crosshair intersection also tracked on or parallel to the line on the cardboard. This test would also uncover any tracking misalignment of the turret axis with the vertical reticle - no? Thought or comments?
 
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gunner69

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Bruce or woods,
Explain how to "align the turret axis" and confirm alignment in a straightforward, efficient manner - preferably without shooting a bunch of ammo? I've improperly presumed a scope turret would track thru its motion parallel with the reticle. But I understand how the mechanical turret movement could be misaligned with the vertical reticle... which would be quite a disappointment to me.

Could a guy secure his rifle/scope in a rifle vise, draw a long vertical/plumbed line on a piece of cardboard, line the vertical crosshair up on the line and crank the scope turret thru its up and down throws and confirm the crosshair intersection tracks up and down the line drawn on the cardboard? I've performed this procedure on all of my long range rigs in order to calculate the true value of my scope turret clicks, by measuring the distance the crosshairs move divided by the number of scope clicks per 100 yards - for a straightforward, measured determination of inches/click/100 yds.

The crosshair on my 3 long range rigs did track parallel with the plumb/vertical line I'd drawn on a large piece of cardboard at 100 yds. I was confirming my scope's click value, but in doing so, I do remember the crosshair intersection also tracked on or parallel to the line on the cardboard. This test would also uncover any tracking misalignment of the turret axis with the vertical reticle - no? Thought or comments?

Yes you could do this but think about this: If your rifle in the vice is not perfectly level and you allign your scope properly to a plumb line on a not level rifle - then what happens to your cant in the field if your rifle is then being held level? Answer: your scope is then canted. That is why the relationship between a level rifle and a plumbed reticle is so important. I really am not here to debate this with some on the board - it is fact. Longrange shooters should eliminate these variables so that they can focus on wind, elevation, physical matters of making such difficult shots.
 

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