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EXD Engineering Vertical Reticle Instrument - brilliantly simple!

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A few weeks back, I read a post by Smoothtrigger about the EXD Engineering Vertical Reticle Instrument, and I immediately knew that I had to have one.

The device arrived this past week, and yesterday I double-checked the scope installation on 8 different rifles. As good a job as I thought I had done previously, 4 of the 8 benefited from some minor fine tuning.

I don't know whether to characterize the instrument as simply brilliant or brilliantly simple!

There is no requirement for what one might perceive to be a flat surface on either the scope or the rifle, because the device helps ensure that the optical centerline is in the same vertical plane as the bore by indexing at two points each on the objective bell and the barrel (or less optimally the top of a picatinney rail on an AR that I double-checked).

One simply supports the rifle / optic combination in the vertical as indicated by the single bubble level, and then rotates the scope within the rings to align the reticle with a suspended plumb bob. I chose to do this indoors so as to minimize any environmental influences.

Hopefully most folks appreciate the critical importance of not having the reticle canted with respect to the optical centerline / bore plane when it comes to shooting at variable distances, whether the technique employed be dialing-in or holding over.

Here is the setup that I used in my foyer to support the rifle:



And a slightly closer pic of the instrument on the scope and rifle:



And finally, the plumb bob in my den about 11 yards away from the rifle. I found that using the bright red string contrasting against the black reticle and background worked excellently:



I quickly learned that by slowly sliding the rear of the rifle vise slightly back and forth sideways (while keeping an eye on the bubble level), it was easy to get extremely precise alignment with the string by watching it appear and disappear behind the reticle along it's length. It is a little hard to describe the technique, but hopefully it makes some sense.

While I have been able to do a good job mounting optics over the past three and a half decades without this tool, using the tool makes it very much quicker and easier, and with an associated higher level of confidence in the results.

Of course, while the true test of any optic setup only comes at the range, it is my expectation that any remaining error will be very slight, if at all.

It would be hard not to recommend this tool to anyone who has the desire to easily and reliably mount a scope on virtually any rifle with a high degree of precision.

Thank you Kevin for originally posting about this fantastic tool.
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No, thank you for an excellent review and explanation of how this tool works.

As we discussed, without a hands on demo of this tool, I haven't been able to light a fire under this. It makes mounting scopes so easy, and with such precision that it's a must have IMO.

Every one of my ranges members that I've shown this to, often when working on their scopes, has purchased one.

But here at RFC it seems most folks either think they've got scope mounting down, or don't quite get what this device does.

I think you may want to modify your threads title to something like.

:Scope mounting for Dummies.
:So you think you know how to mount a scope.:) Sure you do.

You know, a statement that gets people going like ......What, how dare you.

Anyway nice write up.

Smooth.
 

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Very excellent post and review.


I see in this thread four tools that are a must have weather a home smithy or one open to the public for hire.

A quality gun vise
Torque driver
Vertical reticle level
Plumb bob

I might add also a good assortment of driver bits.


Very excellent post sir.

Are you sure your not a salesman for this company? Because I almost pulled out my credit card and bought one at the end of your post.

Then I realized I'm broke for the next few months.


"The biggest communication problem is we don't listen to understand, we listen to reply"
 

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A few questions about this system:

1) I don't see anything here referencing the bore. The device then assumes that the bore is (correctly) drilled left/right centered relative to the outer circumference of the barrel. Is this correct?

2) Can this device work on octagonal barrels?

3) Does this device have several inserts for the piece at the front of the scope for different sizes of objective lenses you may install?

This looks like a pretty good setup. I usually have to fiddle with vertical alignment a bit, as the scopes tend to rotate a bit while tightening the ring screws. This may not stop that, but at least it makes a quick check for when you've finished.

Thanks for the review and pictures!
TE
 

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Discussion Starter · #10 · (Edited)
A few questions about this system:

1) I don't see anything here referencing the bore. The device then assumes that the bore is (correctly) drilled left/right centered relative to the outer circumference of the barrel. Is this correct?

2) Can this device work on octagonal barrels?

3) Does this device have several inserts for the piece at the front of the scope for different sizes of objective lenses you may install?

This looks like a pretty good setup. I usually have to fiddle with vertical alignment a bit, as the scopes tend to rotate a bit while tightening the ring screws. This may not stop that, but at least it makes a quick check for when you've finished.

Thanks for the review and pictures!
TE
1) Yes, the assumption is that the bore is concentric to the barrel OD.

2) I don't see why the device wouldn't work with octagonal barrels. One of the rifles that I tried it on was an AR-type where the hand guard extends over the barrel preventing direct indexing. I specifically chose a rifle with a monolithic picatinny rail hand guard to minimize the error of the barrel not being centered within it.

3) Since the device is indexing a "V" to a circle (typically), there are two points of contact, and the neither the diameter of the scope objective nor the barrel matters. There is an adjustment thumbscrew to accommodate various objective diameters and scope mounting heights.
 

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3) Since the device is indexing a "V" to a circle (typically), there are two points of contact, and the neither the diameter of the scope objective nor the barrel matters. There is an adjustment thumbscrew to accommodate various objective diameters and scope mounting heights.
I see where the thumbscrew accommodates various mounting heights, but not various objective diameters. If the piece the thumbscrew attaches to is circular on the bottom, it would seem you need multiple sizes with different radia. On the other hand, if the bottom of that piece were made parabolic - I could see it functioning with all objective sizes without issue.
 

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Just to add second bit of clarification, as murderman has stated, both the contact areas of device are V shaped. You can see that in the first post.

I've used it with scopes the have 24mm objectives all the way up to 60mm.

It could be used on scopes with even smaller or larger objectives than either of those without any issues.

This photo my help to show how it can fit any objective. As I've stated, the extra levels are not needed.

Smooth
 

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Just to add second bit of clarification, as murderman has stated, both the contact areas of device are V shaped. You can see that in the first post.

Ive used it with scopes the have 24mm objectives all the way up to 60mm.

It could be used on scopes with even small or larger objectives than either of those without any issues.

..
Smooth
That covers the entire range of scope objectives I have. And the picture from the front does make it a bit clearer (better angle maybe).

Thanks for the added clarification! I like this gizmo.
 

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Murderman & Smooth - Thanks to both of you. Mine is now officially backordered from Brownell's. I look forward to getting it and putting it to use. My prior scope alignment tools & techniques have produced satisfactory results, but I think this may in fact be a bit more effective & efficient.

Great write ups & photos. Again, thank you both.
 

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Discussion Starter · #17 ·
Those instructions are verbatim the ones that were included with the device I received, and the illustrations are identical.

At the bottom of the paper, it says "Copyright 2011 EXD Engineering".

Towards the top of the page is the name "One Hole Groups (TM)", with an address of:

P.O. Box 4408
Lawrence, KS 66046

There must be some sort of connection between the two companies, but the question of chicken versus egg is an interesting one.
 

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Mine came in the mail today.....tomorrow I will mount a new scope, and I will publish my review.
This item works great...simple to use, and fast. I was going to use this item outdoors, but since I live in the Suburbs, I am always worried some Neighbor might not like the idea of a Rifle in a gun vise sitting out on my back Deck. I ended up using this Indoors, and used the weights of a German Cuckoo Clock chain as my reference point. The only thing you might want to do is secure the device with a rubber band to keep the item from falling off if you jostle the rifle. It stays pretty much where you place it, but it can fall and possible mar your rifle's finish.

Overall excellent.
 
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