Ok, iI cant find the old thread about how I couldnt get my aimpoint to zero, but what happened was last time, I could not get the shots to group AT ALL. I also noticed that the dot would move in relation to the front site post when looking thru the small aperture (it should be on the top of the post) every time I fired a shot or cycled the bolt.

I took apart the mount, degreased the screws, and put it back together, bottom screws first (which I did the first time too) and torqued all the screws very tight, and tehn installed the top screws as per the instructions.

When I checked it by cycling the bolt, the dot would still move in relation to the post. So I figured it HAD to be the aimpoint, and sent it back to aimpoint. VERY quick turnaround, got a brand new AImpoint within a week.

I mounted that, teh same way, I made the bottom screws (and the top screws) EXTREMELY tight. In fact I bought one of those fold out torx wrench sets from home depot and used that. I torqued the screws so tight it TWISTED THE TORX KEY, and then went back and tried to tighetn it even more with the torx key that came with it, and I couldt budge the screws. I mounted it on the rifle and tightened the tension screw.

then I checked it the same way, setting the aimpoint so the dot is on the top of the front site post, and then cycled the bolt several times. THe dot didnt move at all, so I thought it was all good.

Today I went to the range and fired it. The first group was just about dead on... and real tight, like the size of a quarter (@ 50 yds). SO I really thought I fixed the problem, not to mention I was pretty damn impressed.

so I shot a few more groups.... and they started to open up a bit... and MOVE (up). I checked the dot in relation to the post, and it had moved down the post... so I adjusted it and shot a few more groups. Same thing, groups keep moving up, dot moves down the post.

So now we can say for sure it is NOT the aimpoint. No way two had the same problem and I happened to get both of them.

THis leaves the mount as the problam (and teh RAS II but I seriously doubt that, that thing is rock solid), and the mount FEELS 100% solid but it must be that the recoil is screwing with it.


WTF

Quoted: How tight is the throw lever? C4

pretty damn tight.

Tight enough that you can't move the lever without first loosening the tension screw.

Quoted: I took apart the mount, degreased the screws, and put it back together, bottom screws first (which I did the first time too) and torqued all the screws very tight, and tehn installed the top screws as per the instructions. When I checked it by cycling the bolt, the dot would still move in relation to the post. So I figured it HAD to be the aimpoint, and sent it back to aimpoint. VERY quick turnaround, got a brand new AImpoint within a week. I mounted that, teh same way, I made the bottom screws (and the top screws) EXTREMELY tight. In fact I bought one of those fold out torx wrench sets from home depot and used that. I torqued the screws so tight it TWISTED THE TORX KEY, and then went back and tried to tighetn it even more with the torx key that came with it, and I couldt budge the screws. I mounted it on the rifle and tightened the tension screw. then I checked it the same way, setting the aimpoint so the dot is on the top of the front site post, and then cycled the bolt several times. THe dot didnt move at all, so I thought it was all good. Today I went to the range and fired it. The first group was just about dead on... and real tight, like the size of a quarter (@ 50 yds). SO I really thought I fixed the problem, not to mention I was pretty damn impressed. so I shot a few more groups.... and they started to open up a bit... and MOVE (up). I checked the dot in relation to the post, and it had moved down the post... so I adjusted it and shot a few more groups. Same thing, groups keep moving up, dot moves down the post. So now we can say for sure it is NOT the aimpoint. No way two had the same problem and I happened to get both of them. THis leaves the mount as the problam (and teh RAS II but I seriously doubt that, that thing is rock solid), and the mount FEELS 100% solid but it must be that the recoil is screwing with it. WTF

JeffersonDarcy,
If I read your comments correctly, the bottom screws MUST be tightened first. Then the top. I have  two RAS2 on a Colt M4s with the LaRue Aimpoint mount and it is rock solid. The order of Torx screw tightening is the bottom first, the the top. There will be a gap in the top half of the LaRue mount of about a ~1/4" or slightly less. If you have done this, then maybe the Aimpoint is at fault. I have 6 Aimpoint M2 equipted carbines (with some with alternate scopes - NXS/MR/T), none have ever shown this problem.

Again check your mounting of the LaRue to the Aimpiont. If you have done all of the above, then I would contact LaRue about it and give them very of specifics  info on your mounting & problems. Your problem maybe somthing we have not seen/heard of before.

 

Quoted: Quoted: I took apart the mount, degreased the screws, and put it back together, bottom screws first (which I did the first time too) and torqued all the screws very tight, and tehn installed the top screws as per the instructions. When I checked it by cycling the bolt, the dot would still move in relation to the post. So I figured it HAD to be the aimpoint, and sent it back to aimpoint. VERY quick turnaround, got a brand new AImpoint within a week. I mounted that, teh same way, I made the bottom screws (and the top screws) EXTREMELY tight. In fact I bought one of those fold out torx wrench sets from home depot and used that. I torqued the screws so tight it TWISTED THE TORX KEY, and then went back and tried to tighetn it even more with the torx key that came with it, and I couldt budge the screws. I mounted it on the rifle and tightened the tension screw. then I checked it the same way, setting the aimpoint so the dot is on the top of the front site post, and then cycled the bolt several times. THe dot didnt move at all, so I thought it was all good. Today I went to the range and fired it. The first group was just about dead on... and real tight, like the size of a quarter (@ 50 yds). SO I really thought I fixed the problem, not to mention I was pretty damn impressed. so I shot a few more groups.... and they started to open up a bit... and MOVE (up). I checked the dot in relation to the post, and it had moved down the post... so I adjusted it and shot a few more groups. Same thing, groups keep moving up, dot moves down the post. So now we can say for sure it is NOT the aimpoint. No way two had the same problem and I happened to get both of them. THis leaves the mount as the problam (and teh RAS II but I seriously doubt that, that thing is rock solid), and the mount FEELS 100% solid but it must be that the recoil is screwing with it. WTF JeffersonDarcy, If I read your comments correctly, the bottom screws MUST be tightened first. Then the top. I have  two RAS2 on a Colt M4s with the LaRue Aimpoint mount and it is rock solid. The order of Torx screw tightening is the bottom first, the the top. There will be a gap in the top half of the LaRue mount of about a ~1/4" or slightly less. If you have done this, then maybe the Aimpoint is at fault. I have 6 Aimpoint M2 equipted carbines (with some with alternate scopes - NXS/MR/T), none have ever shown this problem. Again check your mounting of the LaRue to the Aimpiont. If you have done all of the above, then I would contact LaRue about it and give them very of specifics  info on your mounting & problems. Your problem maybe somthing we have not seen/heard of before.

yes, you have to tighthen the bottom screws first. I did that every time I installed it.  I tightened the bottom screws before even putting on the top screws.

There is a gap in the top half, but very small, nowhere tear 1/4". maybe 1/8"

But yea I think its a problem none of us have seen before, I'm about to call LaRue right now....

Quoted: yes, you have to tighthen the bottom screws first. I did that every time I installed it.  I tightened the bottom screws before even putting on the top screws. There is a gap in the top half, but very small, nowhere tear 1/4". maybe 1/8" But yea I think its a problem none of us have seen before, I'm about to call LaRue right now....

weird, if you go to the range this weekend, take something (crayola, chalk stick, etc) and mark to see if maybe the aimpoint is rotating in the rings....sounds like a stretch though, so just an idea.......

JeffersonDarcy,

Try the entire operation all over again and this time, just for the absolute heck of it, don't tighten the upper screws as tight as you have been doing.

It really sounds like a call to LaRue is in order, or if one of the LaRue dealers can actually borrow your aimpoint/larue setup so they can see for themselves.

-Jim

Assuming the bottom rings were tightened first, is it possible to over-tighten the top rings?

I had some wierd behavior with a LT SPR mount, but sold off the scope (Leu M1) before I sorted it out.  The rifle shot like 3/4 MOA with the ACOG, but with the M1 in the SPR mount, it was like 2MOA.   Bottom were tightened first, and all screws were so tight that I  bent the torx tines removing them.  Levers were extremely tight.

(Same scope in MK4 rings shot 3/4 MOA)

-z

Quoted: Just for kicks, do you have another rifle on which you can try the Aimpoint w/the LaRue mount? Just curious, but what kind of rear sight are you using? Is the detent on the front pin holding the pin tight enough? Have you shot the rifle with just the irons? I know these last three are a HUGE stretch, but the problem is so weird I don't know what else to say.

BookHound,
I had considered these a given. But it dosn't hurt to question some other  possibilities.

Quoted: Just for kicks, do you have another rifle on which you can try the Aimpoint w/the LaRue mount?

no. no other flat tops anyway... I have another upper but its A2.

Quoted: Just curious, but what kind of rear sight are you using?

LMT

Quoted: Is the detent on the front pin holding the pin tight enough?

Quoted: Have you shot the rifle with just the irons?

of course. The rifle shoots 1" to 1.5" groups using the irons from teh bench using q3131a pretty easily (when I do my part.... its probably capable of even better accuracy with a magnified optic and /or a better benchrest shooter). It has also been 100% reliable so far, absolutely no malfunctions of any kind in the around 500 rds I put thru it. not that that has anything to do with this I'm just saying how much I like this rifle Its a LMT 14.5" M4 upper (purchased from grant) and its on a Bushmaster lower with a L serial number (which means its also LMT)

Quoted: I know these last three are a HUGE stretch, but the problem is so weird I don't know what else to say.

yea it is really weird. I just got off the phone with Mark Larue and he thought so tooo... his suggestion was to try it on the reciever instead of the RAS II hump to rule out the RAS II, so that will be next.

I don't know when I will get to teh range tho, the closest outdorr range is like 50 miles away

that sucks about the aimpoint/mount.  I'm having no problems with my combo, except my LMT upper.

Quoted: that sucks about the aimpoint/mount.  I'm having no problems with my combo, except my LMT upper.

what problems are you having with the LMT upper?

I would have to go with the suggestion of skipping the RASII, and mounting to the upper itself.  I own a RASII, and love it, but I have installed it once where it actually had a slight cant upward at the muzzle end, after I failed to hold the RASII back against the rail and delta ring tension when installing, IRC.  After I corrected that, all was good.  Point is, the RASII could be the problem and installing that setup on the receiver or another AR15 will help eleminate the posibilities.

Hope this helps.

Tex78

tagged ,, i must know the outcome !

I took it to the range the other day and shot it  with the mount directly on the reciever, which was kidn of hard I had to pick my head way up so the dot was above the irons. It was still doing the same thing, point of aim moving vertically. I wasnt abole to check the dot in relation to the post to see if that was moving, obviously but I'm sure it was too.


I dont think there is any possibility it is the RAS II, now that I checked it this way. But also one thing I realized was that the first time i had this probelm (last month, before I sent the aimpoint back) it was much worse, completely unable to make a group (shots drastically moving verticaly). That time I am sure the lower screws on the mount were not sufficiently tightened, the tensioning screw may have been loose too. The last time it was able to make a group, actually the first was almost dead center, but then the groups started to open up and move vertically(and all screws were very tight). After a while all teh shots were above the oval shoot nc target. anyway, what I am getting at is that it is the same problem, but not as severe as the first time when it happened. if it was teh RAS II, nothing would have changed it would still be completely impossible to group, since I did not change anything with that.....

I'm gonna call Mark Larue again tomorrow to see about sending it back for him to check it out.

I posted this on your older thread, so forgive me if you've already read this:

Can an Aimpoint be rotated 90 degrees in its mount???

If you are sure that the dot is moving only in the vertical plane, then by rotatling the sight 90deg. you could sight in and shoot it (or jar it by cycling the bolt) and see if the dot moves L & R or up and down, revealing if the problem is with the mount or the Aimpoint.

I dont own an Aimpoint as I am an EOthing person myself, so yall don't yell at me if rotating the sight is imposible due to design.

Tex78

Tex, that is a good idea.

HAS anybody here ever had a aimpoint fail like the above mentioned ?

i have owned 10 or better comp series no problems,

just wondering?

Quoted: I posted this on your older thread, so forgive me if you've already read this: Can an Aimpoint be rotated 90 degrees in its mount??? If you are sure that the dot is moving only in the vertical plane, then by rotatling the sight 90deg. you could sight in and shoot it (or jar it by cycling the bolt) and see if the dot moves L & R or up and down, revealing if the problem is with the mount or the Aimpoint. I dont own an Aimpoint as I am an EOthing person myself, so yall don't yell at me if rotating the sight is imposible due to design. Tex78

yes its possible to do that... and its a good idea too....

BUT I already know for a fact that it cant be the aimpoint.

Because I sent the first one back (from the first thread) to aimpoint and got a brand new one. SO, unless not only am I one of the very few people to get an aimpoint with a problem, but I got two with the same problem, its not teh aimpoint.

Quoted: HAS anybody here ever had a aimpoint fail like the above mentioned ? i have owned 10 or better comp series no problems, just wondering?

its not the aimpoint. I think sending it back and getting a new one sufficiently rules out any problem with the aimpoint.

wont to borrow a arms m2268 and spacer or a knights cant mount and see if thats fixes the problem. ?

i have both and will loan you one, but i wont it back .

HIT ME WITH EMAIL IF YOU WONT TO USE ONE OF MY MOUNTS.






LMK

Quoted: wont to borrow a arms m2268 and spacer or a knights cant mount and see if thats fixes the problem. ? i have both and will loan you one, but i wont it back . HIT ME WITH EMAIL IF YOU WONT TO USE ONE OF MY MOUNTS. LMK

yea, that would definately help.

sending email

tag

Quoted: Might want to check the barrel nut. It could still shoot okay with iron sights if the barrel is loose, but would move pretty quickly using an Aimpoint when the barrel got warm. Irons wouldn't show this with the front sight on the barrel.

oh fuck that puts another possibility in this

i hope its not that, how do you check the barrel nut?

oh, I spoke to Mark Larue today, he said he wants me to send the mount with the aimpoint mounted so he can check the whole thing out.

Quoted: Might want to check the barrel nut. It could still shoot okay with iron sights if the barrel is loose, but would move pretty quickly using an Aimpoint when the barrel got warm. Irons wouldn't show this with the front sight on the barrel.

also wouldntr that make the point of aim move horizontally too?

its been all vertical movement

Tagged

Quoted: Tagged

+1

Tagged. Intriguing.

Jefferson, how tight is your lever on your LMT upper? On mine it seems I had to use the screw adjustment quite a bit to get the mount solid.

Quoted: Tagged. Intriguing. Jefferson, how tight is your lever on your LMT upper? On mine it seems I had to use the screw adjustment quite a bit to get the mount solid.

I had to tighten it quite a bit as well.

I didnt have it mounted to the upper, I had it mounted to the RAS II hump. Not that that matters, a rail is a rail.

Update:

Mark Larue checked it out, he confirmed that the rings are properly installed and tight.

He said there was a possibility that the rail on my RAS II is thin so he's gonna make a special tensioning screw for it.

Another possibility (as mentioned in this thread) is that the barrel itself is not tight enough. And its possible that when the barrel heats up from being fired, the metal expands and it tightens it up, which makes the barrel tilt a bit upwards (because it was sagging because it is loose). The one thing with this though, is that when the barrel cools, the point of aim does not move (referenced by the position of the aimpoint dot on the front site when looking thru the rear... it moved down the front site post after firing a few groups, but then it remained there even after the barrel completely cooled) also origially, before the aimpoint was sent back, the movement was in the other direction (dot going up as opposed to down).

I also called LMT and let them know what was going on and that the barrel was a possibility, and that I can send it back whenever if I want them to check it out.

When I get my aimpoint and mount back from Mark LaRue, I will first take off and re-mount the RAS II, then mount teh aimpoint with the new adjustment screw, and if it still happens I'll send the upper back to LMT for them to check it out.

I had the exact same thing happen wth the same setup on my new build.  Last month at Thunder Ranch I could not get the gun to maintain constant zero.  I literally was fiddling with the Aimpoint controls 2-3 times per day.  Anyway, I have no idea why this is but this thread gives me some ideas as to where to start looking.

Quoted:
I had the exact same thing happen wth the same setup on my new build.  Last month at Thunder Ranch I could not get the gun to maintain constant zero.  I literally was fiddling with the Aimpoint controls 2-3 times per day.  Anyway, I have no idea why this is but this thread gives me some ideas as to where to start looking.[/quote

what was your setup?

edit: duh I feel stupid... same setup.

Well I have ruled out the aimpoint (by it being replaced) the mount (Mark LaRue checked it, no problems) the upper is in the process of being ruled out.

very well may be the RAS II.

u should get a daniel defense or larue FF system

Quoted: u should get a daniel defense or larue FF system

if it still happens when I get all my stuff back, I will be doing that. Since Grant is testing the whole thing out... my upper with a different aimpoint and another upper that he knows works with my aimpoint, if it works fine for him and not for me, it HAS to be the RAS II (although I really dont know how that could be the problem, that thing seems very secure)

if that is the case I will be getting a DD or LaRue or just a regular non FF RAS. i really dont owant to because then I'm out like $400 for the RAS II and special larue mount.

Quoted: I took it to the range the other day and shot it with the mount directly on the reciever, which was kidn of hard I had to pick my head way up so the dot was above the irons. It was still doing the same thing, point of aim moving vertically. I wasnt abole to check the dot in relation to the post to see if that was moving, obviously but I'm sure it was too.

How could it be the RAS2 if you have already mounted the unit directly to the upper receiver and still have the problem?

Quoted: Quoted: I took it to the range the other day and shot it with the mount directly on the reciever, which was kidn of hard I had to pick my head way up so the dot was above the irons. It was still doing the same thing, point of aim moving vertically. I wasnt abole to check the dot in relation to the post to see if that was moving, obviously but I'm sure it was too. How could it be the RAS2 if you have already mounted the unit directly to the upper receiver and still have the problem?

slim possibility that when it was mounted to the upper directly I didnt tighten the tension screw enough.

unlikely but if its not the mount, aimpoint or upper, thats all it can be.

It sounds like a problem with the upper.  I guess we need to wait for the results from Grant.