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Razorhunter
02-04-07, 00:35
I have just received my TA11F, and I'm attempting to get my chevron reticle/BDC ladder lined up perfectly "plumb" or "vertical" too.
Mine is leaning a little bit to the left, almost where the tip of the chevron is pointing to 11 o'clock, or more like 11-thirty.
It's just a little, but in all reality, it's a LOT, and enough to really piss you off, and annoy the hell out of anyone who is even SLIGHTLY particular about their setup.
Not to mention this throws off accuracy at long ranges.

Now I've done a lot of machining work in my time, and I can tell you that it looks like MINE is caused by the damn tensioning screws on the TA51 mount.
It's NO COINCIDENCE, that the reticle is pointing in the direction of the screws that tighten down and hold the TA51 mount to my rifle's flattop (Colt 6920 BTW).

SO, I'm not sure what to do as of now. I could shim it, but that's not the real fix, and surely would eat away at me for all of eternity.
UNLESS I can loosen the TA11 from the TA51 base, and somehow get a little adjustment out of that, then I don't have an answer.

UNLESS OF COURSE, a LARUE mount, will solve this entire problem in its entirety??? Regardless, I would still like to fix this problem until I get a Larue mount, as I just am not willing to accept the fact that I drop $1000 on an optic, and can't get it level using the TA51 mount that came with it.

I can't believe I haven't seen more posts on this problem. (I HAVE seen it mentioned a time or two, but that's it)
I bet a LOT of guys DO really have this problem, and just aren't noticing it, or don't care.
I can't count the number of times, I've met a new deer hunter, and when I looked through his scope, his damn reticle was so out of level it made me dizzy.
Some guys just don't get it, and many others just don't care.. More than ANYTHING, many guys wouldn't EVER notice an 11 0'clock or an 11-thirty lean....

Anyone got comments on this????

Robb Jensen
02-04-07, 08:17
I haven't seen one that was messed up from the factory, if yours is I would send it and the mount back to Trijicon after verifying that the rail on the upper reciever is 100% straight too.

Have another shooter look through it as it might be straight but appear to be crooked.

I'm a left-eye dominant right handed shooter and when I mount scopes for people sometimes it'll look great for me but crooked for a right-eye dominant right handed shooter.

I've been shooting cross-dominant for over 32yrs so I'm not going to change to left handed shooting. For a year I even shot long guns left handed. I can shoot everything just as well left handed (somethings a little better) but I'm slower and a little sloppier. So I do train weak handed (left) quite a bit. I'm actually left handed in somethings like bowling, throwing a baseball or football. I was suppose to be a southpaw but one of my parents thought it was weird when I was little and would make me use my right hand to color/draw/write.

C4IGrant
02-04-07, 10:20
There could be several things causing this. The first thing I would look at is your upper receiver. It is VERY common for them to be canted. Take the ACOG and mount it on another AR and see what you get.




C4

Razorhunter
02-04-07, 12:20
Well guys,
I've been playing with this setup all morning long, until my arms are about to fall off from handling the rifle in so many positions.
I've tried different positions on the receiver, and I've tried different tightening techniques.
I just don't know what is the problem at this time.
Part of me says it's all an optical illusion, and the problem is that I have a tendency to naturally cant the rifle (which makes the BDC look canted), (but honestly, I've always been real good about "putting the ol good-eye on it", and KNOWING when somethings straight and level, or when something is canted.
You just get that feeling when you KNOW something is not lined up right.

Anyhow, I wish I had an ideal way of clamping the rifle in a position where I could level the receiver, so I could then be SURE about whether the BDC ladder is plumb or not.
I sold off all of my machinist levels a while back, and they are very expensive.

One other method I am thinking of trying, is to hang a plumb bob (string with weight on the end) from the ceiling in my shop, and use that as a perfectly straight, plumb, level reference point.
I have used this technique in the past with limited success.

I don't have any buddies around with other rifles to try the ACOG on, and I don't have anyone else around who would give their opinion.
I am thinking I should definitely try a Larue mount, but I would like to know if you guys can explain to me exactly HOW the Larue mount clamps to the receiver?
Does it clamp in a similar manner as the TA51 mount? (clamp screws on one side?)
HOW does the Larue mount clamp down, and does anyone have a pic of it?
I've seen many pics of them online, but never a pic that showed a close enough pic of the CORRECT side of the rifle...

Thanks for any help guys...
I'm off to look for a pic of the Larue mount..

C4IGrant
02-04-07, 12:53
The LT mount attaches basically the same way that the TA51 mount does (engages the underside of the rail). I could only find one pic of the underside of the LT lever and not sure it will really help you out.

If you want, you can buy a LT ACOG mount from me and if it doesn't fix your problem, you can send it back for a refund.

Couple other thoughts, put the ACOG on different parts of your upper receiver to see if that fixes it. Also, try reversing it on the receiver (so it is pointing at the stock). We want to try and see if the receiver is canted (which is what I think is wrong).




C4



http://www.gandrtactical.com/images/archive/LT/LT%20107%20on%20SF%20M900A2.JPG

Paulinski
02-04-07, 13:01
One way to securing the upper receiver is via action block. Brownells and DPMS both sell those tools. If you own an AR it is a good idea to pick up such a tool.
With the upper receiver secured you can check to see if your Acog is indeed canted.

http://www.dpmsinc.com/store/products/?prod=600&cat=1450

Paul

Razorhunter
02-04-07, 13:01
THANKS for that pic Grant. It does help.

I have tried mounting it in various positions on down the line, and it all shows the same result (BDC ladder canted slightly to the left at 11 o'clock).
However, I'm STILL wondering if this is my natural grip on the rifle, which might cause this.
It's quite a bit more difficult to KNOW if your ACOG's BDC ladder is level/plumb, as compared to leveling/plumbing a regular cross hair reticle on a deer/sniper rifle. When you have LONGER reticle lines (as well as a horizontal stadia/reticle line) to work with, it's much more noticeable, and easier all around.


GREAT IDEA on turning the ACOG around to face the other way Grant. ONLY issue then, making sure I am holding the rifle in the same position as when the scope it mounted in the proper direction.
Still though, I'm off to try this test, and see what happens..

Really wish I had someone around, who knew ANYTHING about rifles, who could look at it, and give me a second opinion.
I really do think the BDC ladder is canted though. I've always had a natural "feel" for this sort of thing..

Stay tuned, and THANK YOU Grant!