ADM MRO Absolute Co-witness mount more like a lower 1/3?

[flyboy1788]

Anyone else have an ADM absolute cowitness mount for their MRO? Anyone else think it's more like a typical lower 1/3? When the irons are lined up the red dot is on the top of the front post in what certainly seems to be 1/3 of the way up from the bottom. Figured absolute means absolute and lower 1/3 means lower 1/3. Are there variances between manufacturers? And yes I checked and double checked the model number, it is an absolute mount for sure. Not a deal breaker but somewhat annoying.
ETA: Measured the centerline of the optic from the base of the rail with calipers and it seems to be right at 1.56"
Height from base of rail to center of troy ghost ring as well as the top of the front sight post seem to both be right around 1.38"
Also worthy of note, Vortex's definition of absolute cowitness is a centerline of 37mm (1.46") above the rail and their definition of lower 1/3 is a centerline of 40mm (1.57") above the rail.
Primary Arms 30mm magnifier mount claims to be lower 1/3 and has a self proclaimed centerline of 1.65" above the rail.

[gaijin]

I have one with a MRO.
With my KAC BUIS dialed in (200 yd) and MRO dialed in same- the top of dot is about even with top of FS.
In my case no, I don’t see a lower 1/3.

[flyboy1788]

I have one with a MRO.
With my KAC BUIS dialed in (200 yd) and MRO dialed in same- the top of dot is about even with top of FS.
In my case no, I don’t see a lower 1/3.

Hmm, all the more confusing. Thanks for your input.

[GH41]

Hmm, all the more confusing. Thanks for your input.

While there are no rules written in stone most would use lower 1/3 on a rifle with a fixed front sight to improve FOV and use absolute with folding sights to keep the RDS closer to the bore. With either lower or absolute the dots position relative to the sights makes no difference... If you are using the RDS correctly and looking at the target you won't even see the front sight.

[flyboy1788]

While there are no rules written in stone most would use lower 1/3 on a rifle with a fixed front sight to improve FOV and use absolute with folding sights to keep the RDS closer to the bore. With either lower or absolute the dots position relative to the sights makes no difference... If you are using the RDS correctly and looking at the target you won't even see the front sight.

Yeah I hear what you're saying and at the end of the day it's not a huge deal if it isn't perfectly absolute cowitness, I'm just OCD about my gear and wanted to hear the consensus as to whether other people have the same thing going on. Still like the mount however it's definitely more like the lower 1/3 reference in this image: https://cdn.shopify.com/s/files/1/02...g?v=1492457891

[Captains1911]

Although not exactly the same, I’m using an ADM Aimpoint T1 mount with a Primary Arms Advanced Microdot that is supposed to absolute co-witness, but is actually closer to a lower 1/3.

[Mr McSimon]

I've got an ADM co-witness QD for MRO and know what you're asking about. I ran into the same kind of issue with the T1 mount a while back too, and what's happening is that you're ending up with a 1.53" riser height mount vs a 1.41" riser height, both considered absolute co-witness. What GH41 says is true, there don't seem to be any true standards, but there is some consistency. Here's a link to a thread I started asking a similar question earlier this year, with a particularly good answer/summary from Slippers. https://www.m4carbine.net/showthread...ess&highlight=

For me it's less about being OCD and more about my astigmatism, and being able to use the BUIS as a focal aid for the red dot when the extra clarity is needed. I'd like to run my red dot's 1/3 for the extra FOV over the FSB, but I can see through the FSB in co-witness well enough that the trade for the aid is worth it, meaning I get to keep drinking the kool-aid.

[flyboy1788]

Although not exactly the same, I’m using an ADM Aimpoint T1 mount with a Primary Arms Advanced Microdot that is supposed to absolute co-witness, but is actually closer to a lower 1/3.

Appreciate the review.

I've got an ADM co-witness QD for MRO and know what you're asking about. I ran into the same kind of issue with the T1 mount a while back too, and what's happening is that you're ending up with a 1.53" riser height mount vs a 1.41" riser height, both considered absolute co-witness. What GH41 says is true, there don't seem to be any true standards, but there is some consistency. Here's a link to a thread I started asking a similar question earlier this year, with a particularly good answer/summary from Slippers. https://www.m4carbine.net/showthread...ess&highlight=

For me it's less about being OCD and more about my astigmatism, and being able to use the BUIS as a focal aid for the red dot when the extra clarity is needed. I'd like to run my red dot's 1/3 for the extra FOV over the FSB, but I can see through the FSB in co-witness well enough that the trade for the aid is worth it, meaning I get to keep drinking the kool-aid.

Great, thanks for the post. Definitely seems to be what I've found as well in regards to not much of a set standard but rather a loosely defined concept.

[flyboy1788]

Although not exactly the same, I’m using an ADM Aimpoint T1 mount with a Primary Arms Advanced Microdot that is supposed to absolute co-witness, but is actually closer to a lower 1/3.

Appreciate the review.

I've got an ADM co-witness QD for MRO and know what you're asking about. I ran into the same kind of issue with the T1 mount a while back too, and what's happening is that you're ending up with a 1.53" riser height mount vs a 1.41" riser height, both considered absolute co-witness. What GH41 says is true, there don't seem to be any true standards, but there is some consistency. Here's a link to a thread I started asking a similar question earlier this year, with a particularly good answer/summary from Slippers. https://www.m4carbine.net/showthread...ess&highlight=

For me it's less about being OCD and more about my astigmatism, and being able to use the BUIS as a focal aid for the red dot when the extra clarity is needed. I'd like to run my red dot's 1/3 for the extra FOV over the FSB, but I can see through the FSB in co-witness well enough that the trade for the aid is worth it, meaning I get to keep drinking the kool-aid.

Great, thanks for the post. Definitely seems to be what I've found as well in regards to not much of a set standard but rather a loosely defined concept.