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Old June 21, 2018, 12:50 AM   #1
marine6680
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American Defense Cantilever ACOG Mount First Impressions

A quick first impression review of the American Defense Cantilever ACOG mount.


It does what it is advertised to do, give those who do not like to shoot nose to charging handle, a more natural head position on the stock, while getting proper eye relief with the ACOG.

I have yet to confirm, but the channel in the ACOG base seems to be at the proper height to use the channel at a ghost ring for the front sight. (using MBUS Pro, on a free float set up) I need to measure the height vs the rear sight, but the cheek weld feels right.

The cheek weld looking through the scope isn't bad. Its a bit more heads up that a typical red dot checkweld would be though.


Some negatives... It is a tad higher than I would prefer, but usable.

If they offered a version that was a little shorter, for clearing low profile sights, that would be a good way to go. Not all sights need that much clearance. (though you would lose the ability to use the channel as an aiming reference with a front sight)


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Old June 21, 2018, 02:51 AM   #2
mellow_c
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Yikes!

I like the acog, but i don't think i could get used to holding my head up that high. I'd sacrifice the BUIS to mount the acog all the way to the rear of the upper and then run the stock a bit shorter if needed for proper eye relief.


I hope it works for you though. It obviously works for some, otherwise they wouldn't make it.
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Old June 21, 2018, 07:58 AM   #3
Bartholomew Roberts
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If the mount is high enough to use the tunnel on an ACOG as a ghost ring for the front sight, then it is basically close to the same height as a detachable carry handle.

The difference being the detachable carry handles can probably be found cheap or free in someone’s cast off parts box and they have built in 600m adjustable iron sights you can use through the tunnel without having to flip up.

My guess is that this mount sits a bit lower than a carry handle and while you probably could adjust the front post to use the tunnel as a giant ghost ring, you’d basically make your flip rear sight useless with that much elevation change.

Having said that, I’d look real hard at a detachable carry handle mounted ACOG if this is the height you need for your uses.
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Old June 21, 2018, 08:28 AM   #4
marine6680
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The issue with the charging handle is that the sight still sits farther forward.

The point of this mount is to get the optic farther to the rear than even mounting it at the back of the rail gets you.

It does sit a tad lower than the actual rear sight for use as a makeshift ghost ring. It would work well enough out to 25yds or so for COM hits.


It does sit a bit high, I do think they need to offer this in two versions. They could make one that is about .25in shorter and still clear the smaller BUIS like the MBUS Pro, KAC, and others, then this version for larger BUIS.


I am torn a bit by the mount. It does do what it claims, and the height is really only a minor point. The cheek/chin well works and is comfortable enough for my uses. Though I would like it a little lower.

Subjectively... It's not very nice to look at.


I have yet to see one of these out in the wild or even pics of one mounted on a rifle... So I took the chance.
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Old June 22, 2018, 12:57 PM   #5
DaleA
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Quote:
Subjectively... It's not very nice to look at.
I have yet to see one of these out in the wild or even pics of one mounted on a rifle... So I took the chance.
Good for you! That's how we find things out. For most of my shooting life I found or was told of a way to do something and that was that. Once something 'worked' I quit looking for anything better. I missed out on a LOT of stuff.

I appreciate the information and the analysis.
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Old June 22, 2018, 02:49 PM   #6
riffraff
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I bet left-eye right-hand shooting would be very comfortable at that height..

Wondering - what is the benefit of moving the optic back? Seems like it would push the weight of the rifle out forward and contribute to strain.
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Old June 22, 2018, 08:47 PM   #7
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Moving the optic back, should move weight back, but due to how forces work, in this case, the weight of the optic is applied at the point where the mount clamps to the rail. Basically exactly where it would be applied normally.


The benefit of moving the optic back... Is that in this case, the optic is an ACOG.

This model ACOG has an eye relief of 1.5in, less than half of many scopes.

This means you have to have your face far forward on the stock, and I find it uncomfortable.


I ended up returning the mount. Its higher than I want, and goofy looking.

I picked up a KRAM spacer and a standard ACOG mount from ADM. This will give me the same basic setup, with the optic pushed back, but with less height.
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Old June 22, 2018, 11:03 PM   #8
riffraff
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Quote:
Originally Posted by marine6680 View Post
Moving the optic back, should move weight back, but due to how forces work, in this case, the weight of the optic is applied at the point where the mount clamps to the rail. Basically exactly where it would be applied normally.


The benefit of moving the optic back... Is that in this case, the optic is an ACOG.

This model ACOG has an eye relief of 1.5in, less than half of many scopes.

This means you have to have your face far forward on the stock, and I find it uncomfortable.


I ended up returning the mount. Its higher than I want, and goofy looking.

I picked up a KRAM spacer and a standard ACOG mount from ADM. This will give me the same basic setup, with the optic pushed back, but with less height.
Doesn't really matter where the object is mounted rather it matters where it's positioned. It does move the weight aft on the rifle by moving the ACOG back - although technically because of the cantilever the weight of the object is probably pulling "up" on the rail, ie if you just set it on the rail without attaching it the setup would tip backwards and fall.

My thinking was, since the ACOG is so far back you are going to have to extend the stock, pushing the rifle away from you... But that's wrong because of the eye relief, actually sounds like you might end up with the stock in the same position you'd have it with another optic since your eye needs to e closer to the ACOG?
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Old June 23, 2018, 12:48 AM   #9
marine6680
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Cantilevers are an odd set of forces, ultimately the force must be transmitted from the optic into the rifle through the mount itself, with the weight bias being to the rear of the mount.

BUt yes, having the optic farther rearward allows the stock to be in the same position I would use for other optics. So it feels more comfortable.
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Old June 23, 2018, 02:46 AM   #10
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marine,

In regards to your post #7.

Wow! I think you found it!... should even clear the metal magpul rear sight. And so much lower and leaner.

It might not put the optic as far back it looks like, but you can sacrifice your length of pull a little bit if you have to, maybe?

Along with the other ideas you mentioned in other threads, it sounds like you got it all worked out.

Good job buddy. I'd love to give something like that a try!
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Old June 23, 2018, 02:26 PM   #11
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Hopefully I won't lose much with the new setup.

I know I can move the BUIS, but I do not want to do that. Just my personal hangup.

If I was willing to move the BUIS, Larue makes a mount that allows the scope to sit further back as well, but it requires you to mount to the back of the receiver, and the scope would be cantilevered back. But it maintains the same mount height as the standard mounts.
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Old June 26, 2018, 03:16 PM   #12
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Depending on what type of stock you are running, you could try to add some spacers to extend length of pull.
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Old June 26, 2018, 04:12 PM   #13
marine6680
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The problem is the very short eye relief on the ACOG...

I can get a comfortable head position and stock length no problem... But the scope is too far forward to see through properly.
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