question about the 1.5X ACOGs

[masakari]

So i saw this picture online:
http://www.policemag.com/_Images/art...nal-1104-2.jpg
And it got me thinking... what is the maximum distance your eye can be away from the 1.5X ACOGs? Would the above config work?
i ask because i have an M1A with an ultimak rail and would LOVE to have an ACOG mounted forwards like that.

[rob_s]

That seems too far to me.

Eye relief on magnified optics isn't a matter of minimum or maximum only. It's typically given as a fixed number (although on variables you'll sometimes get a range, which cracks me up, am I supposed to move my head around as I adjust the magnification?).

That optic would appear to be the TA26S-10 which has a listed eye relief of 2.4 inches. I can tell you that I have a TA33R-8 which has a listed eye relief of 1.9 inches and I do find that number to be lower than where I actually place my head, but I can't see the TA26 number being off by enough to make the mounting shown in the picture possible.

Unless you have some physical limitation that makes the ACOG preferable, I'd just put an Aimpoint H-1/T-1 in that location and be done with it. Especially one of the new 2 MOA versions.

[masakari]

That seems too far to me.

Eye relief on magnified optics isn't a matter of minimum or maximum only. It's typically given as a fixed number (although on variables you'll sometimes get a range, which cracks me up, am I supposed to move my head around as I adjust the magnification?).

That optic would appear to be the TA26S-10 which has a listed eye relief of 2.4 inches. I can tell you that I have a TA33R-8 which has a listed eye relief of 1.9 inches and I do find that number to be lower than where I actually place my head, but I can't see the TA26 number being off by enough to make the mounting shown in the picture possible.

Unless you have some physical limitation that makes the ACOG preferable, I'd just put an Aimpoint H-1/T-1 in that location and be done with it. Especially one of the new 2 MOA versions.

I do understand all of that, and I too have a TA-33 on my M4 and my head is placed quite far from it, so that and this picture is what had me thinking. Would anybody be able to try it out just to see the distance they could get away with with any of the 1.5X ACOGs?
im not fond of aimpoints, or other electronic optics, so my plan has been to wait for a Trijicon Scout scope (which as per Trijicon representatives is in the works) but this wait is getting frustrating, and my Burris 2-7X pistol scope is bulky, heavy, and on its third trip back to the factory for repair.

[SomeOtherGuy]

I owned and briefly used a TA26R4, a version of the 1.5x16 ACOG. It was listed as 2.4" eye relief, but my experience was that eye position was very flexible and you still had a decent sight picture out to 5" or more from the ocular. However, it appears that the ACOG in the photo you posted would be more than 5" from the eye in any reasonable shooting position.

However, Trijicon also made a 1.5x24 ACOG (if I remember correctly) that was listed as having 3.6" eye relief (again, IIRC) and presumably was even more flexible on eye relief than what I had experience with. If the pictured ACOG is that model, it's possible that the sight picture would be useable, though definitely at the far end of the useable range.

[Doc Safari]

I had a TA44SG10 that had way less eye relief than I wanted. In fact, I got rid of it before ever firing a single round through the rifle with it mounted.

It needed to be mounted all the way back on the receiver where a rear BUIS normally goes, or you would have had to look through it nose-to-charging handle.

I believe quoted eye relief distances for this optic are overly optimistic.

[Dienekes]

Don't believe that would work. The eye relief on my TA47 1.5X is long, but not THAT long.

FWIW I have a TA33 3X on an M1A in a Smith mount, and the rear of the optic is about at the rear of the receiver. Not nearly as much eye relief as the TA47. I must confess I don't use it all that much (fully loaded it porks out at slightly over 13 pounds, and I'm not getting any younger!).