View Full Version : ACOG placement - eye relief
I apologize in advance if this sounds like a dumb question. But I've always felt that if you don't know something, it's best to ask.
After much debating, I decided to purchase a Trijicon ACOG TA33-8, for LE use on my LMT M4. With all my other optics, there has been a small, "sweet spot", and it was obvious that if you strayed too far from that. With this TA33-8, I can move from what I call "full field", where the image inside the scope maxes out the available area, to actually putting my eyeball up against the lens, although the image shrinks somewhat, leaving a dark circular area surrounding the image.
What is the proper way to determine the correct position to mount it, in regards to eye relief? Should the field of view through the scope pretty much max out the available space? Would it be wise to allow some leeway, in case I cannot obtain NTCH positioning?
MisterWilson
08-12-08, 15:17
My TA33 R-8 has the most forgiving eye relief of anything I've ever looked through. I usually shoot on the 1st or 2nd notch just outside NTCH and I've had no problems with having it as far back as possible, closest to a Troy BUIS.
http://i138.photobucket.com/albums/q252/mastersqurm/Guns/DSC08527.jpg
Also, a LaRue mount is absolutely required. The factory mount places it too bloody high while the LT is at just the right height.
kalikraven
08-12-08, 18:37
I'm glad to have read this post. I just bought one from grant and it was delivered today. I'll have to wait till next week to play with it but this is good news for me. I had originally asked about the TA11d because it has 2.4" of releaf, but grant recomended the 33R-8 which is a much smaller ACOG.
I'm very happy with mine; I previously owned a 4x32 TA-31 and couldn't get used to the short eye relief. Shooting the TA-33R8 is easy.
Somehow I think that Trijicon mismeasured the eye relief on the TA33 models. I've found that they can sit much further forward than the numbers would appear to indicate. However, I have also found that I can move them fore and aft up to two notches without issue, so perhaps they simply quoted the lowest eye relief.
When I added the Vltor Emod in place of their standard stock, I did have to move it back a bit though.
http://i134.photobucket.com/albums/q111/rob_s/gun%20stuff/6520-01.jpg
http://i134.photobucket.com/albums/q111/rob_s/gun%20stuff/BIB-starboard.jpg
MisterWilson
08-14-08, 12:42
Rob, don't be lazy, time your comp.
:p
Judging from the replies, I think I must have been unclear with my initial question.
With the TA33, when looking through the scope, is it better to have the image appear within an "o" within the larger "O", or should it be placed to get the image as close to an "O" within the "O"? I note that with the "o" inside an "O", I see the writing "3X 223F" at the bottom of the larger "O".
Yes, I admit, sometimes I'm dense.
MisterWilson
08-14-08, 12:49
If I understand what you're asking, to answer your question: closer is better than than farther.
Rob, don't be lazy, time your comp.
:p
Supposedly it doesn't work that way / doesn't matter. The washer that came with it is that weird stainless thing that doesn't appear to be a crush or a peel.
Judging from the replies, I think I must have been unclear with my initial question.
With the TA33, when looking through the scope, is it better to have the image appear within an "o" within the larger "O", or should it be placed to get the image as close to an "O" within the "O"? I note that with the "o" inside an "O", I see the writing "3X 223F" at the bottom of the larger "O".
Yes, I admit, sometimes I'm dense.
I'm not sure I understand your question, but...
I position the scope such that the body disapears as much as possible. Basically the one on the left looks here.
http://i134.photobucket.com/albums/q111/rob_s/gun%20stuff/1.5XVS3X.jpg
OK, so the writing "3X 223F" should not be visible in normal use?
OK, so the writing "3X 223F" should not be visible in normal use?
Honestly? The fact that you're even asking this tells me you're not out shooting the damn thing! :p
Get it roughly where it looks like you want it to with a perfect cheek weld, and then go shoot it. Get it zeroed, move it fore and aft a bit, rezero, ets. Then go RUN the gun and stop reading the reticule!
Perhaps instead of "normal use" I should have said "normal placement". I was trying to further iterate my question, hoping it would make more sense.
Of course during actual firing use I wouldn't be reading the writing inside the optic. But thanks for the info.
Supposedly it doesn't work that way / doesn't matter. The washer that came with it is that weird stainless thing that doesn't appear to be a crush or a peel.
I just used standard crush washer with my Vltor comp so far it has held up fine.
MisterWilson
08-14-08, 14:56
Yeah but it looks like he has a peel washer.
Yes they ship with this funky peel washer I was never a fan of them so I used a standard crush washer.
At the risk of sounding ignorant again, what does a washer have to do with eye relief on an ACOG?
MisterWilson
08-14-08, 15:12
It was a comment ribbing on Rob for not timing his FH probably because it's a pain in the butt that degenerated into a full on derailment.
Battl3fr0nt
08-15-08, 23:47
The TA33 is a good little optic, I would have to say mount it to where the rear of the ACOG is a bit past the charging handle. I have my TA31F mounting like that and it works fine and the TA33 only has about .4" more eye relief so it's about the same.. only thing I dont like about it is the FOV but other then that its an ACOG and nothing can beat an ACOG :D
Powered by vBulletin® Version 4.2.5 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.