Cant sight in AR [Archive] - Glock Talk

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bigdough666
01-26-2011, 20:47
Long story short, I cannot get my AR sighted in. Its a flat top upper with YHM BUIS setup. The gun shoots tights groups centered but about 3" to the right. Either way I adjust the rear sight, the gun still hits in the same spot which is what is freaking me out. I can adjust all the way to the right, hits right, all the way left, hits right. So, is my gun/barrel messed up or are the sights bad?? Should I take them off completely and start over? Or buy a new set and start over?? What sight do you guys recommend if so? I was thinkin Magpul. Any help would be appreciated, thanks.


BTW - before you suggest its the shooter, I had 2 of my friends shoot the gun also with the same results.

Jeff82
01-26-2011, 20:58
How's your flash hider/muzzle break looking? Not loose or got any shiny spots on the inside, does it?
Crown look good?
Sights are tight like they're supposed to be?
Rear aperture moving in accordance with how much you adjust it?

Camu Mahubah
01-27-2011, 02:03
Can you take the upper off the gun and the bcg out and then look down barrel and at an object at I dunno as close as you can estimate to 25m...then make sure the barrel doesn't move and then look through the rear sight. This is what I had to do to get my AR zeroed. Well at least it was the start of the process.

I wouldn't change the sight just yet...

Some ammo likes to shoot to the right in my gun...but yes I have seen that sight and isn't it based on metal tension to grip the gun?

That's some late night advice there...I hope I made sense...I'll check back in the AM...

K. Foster
01-27-2011, 07:45
What distance are you shooting? Are you sure the rear aperture moves when you adjust it? When you make adjustments, does your point of impact change at all?

Another Miller
01-27-2011, 08:03
Sounds like a sight issue.Something is slipping back each time you fire it.



Id try a different sight, like a red dot.

bigdough666
01-27-2011, 10:51
Whoa lots of info.

I'm at work so I can't check the rifle now, I'll check it when I go home.

To answer some questions, I'm shooting right now around 25 yards, just to get a feel for the rifle.

As far as I can tell, the sights are on nice and tight.

I'm sure the sight is moving when I make adjustment, it's a drastic change from all right to all left.

No change in the poin of impact what so ever. It hits dead center but 3" to the right. Adjust the rear sight left or right, no change.

I am evetually goin to an ACOG setup but I want the BUIS accurate as well.

BBJones
01-27-2011, 10:54
Is this @ 25, 50, 100 yards?

Because you are getting tight groups sounds like the sight is not adjusting. Do you have access to any other sights that you can test this theory?

K. Foster
01-27-2011, 11:14
I'm sure the sight is moving when I make adjustment, it's a drastic change from all right to all left.

No change in the poin of impact what so ever. It hits dead center but 3" to the right. Adjust the rear sight left or right, no change.

If you are moving the rear sight to itís left and right limits, and it doesnít effect your point of impact... either the sight isnít moving as it should or you are doing something wrong, no offense intended. What diameter are your groups and how many shots in a group.

expatman
01-27-2011, 12:29
I agree with the above post. It should be physically impossible to move the sights from the extreme left to the extreme right and not have a change in POI. There has to be something missing in the description of the problem.

Flashbang1063
01-27-2011, 12:57
I don't even know how that is possible if the rear aperture is actually moving.

Are you sure the rear sight aperture is moving and it's not just the adjustment screw turning? Place a mark on the aperture and the sight base to see if it is moving.

DeltaNu1142
01-27-2011, 13:04
Are you using only the close-range aperture? Try the distance one. It could be that your eyes are "fuzzying" the rear sight enough that you're not centering the front sight in the aperture... although that seems pretty far-fetched. It's the only thing I can think of if everything you're saying is true.

bigdough666
01-27-2011, 17:45
http://i257.photobucket.com/albums/hh211/V8KLLA/DSC_0201.jpg
http://i257.photobucket.com/albums/hh211/V8KLLA/DSC_0202.jpg

http://i257.photobucket.com/albums/hh211/V8KLLA/DSC_0203.jpg
http://i257.photobucket.com/albums/hh211/V8KLLA/DSC_0204.jpg

http://i257.photobucket.com/albums/hh211/V8KLLA/DSC_0205.jpg
http://i257.photobucket.com/albums/hh211/V8KLLA/DSC_0206.jpg

Yup, pretty sure its moving. Thats whats freaking me out the most. Doesnt make any sense at all.

Checked out the gun. Flash hider is good, not loose, no shiny spots. Both sights are nice and tight.

bigdough666
01-27-2011, 17:46
Hell, just looking at those pics I just posted, does that rear right look crooked?? Maybe its just how im holding the gun, i dont know.

MisterPX
01-27-2011, 18:00
Lookslike your sight moves fine, which can only mean one thing, teh shooter. Your freinds shot it at one extreme, as well as the other, and had teh same no change on POI?

ETA: Are you sure that's a YHM sight? Retention knob know looks like nothing I've ever seen on their stuff. Also, haven't seen a sight like that on their website.

bigdough666
01-27-2011, 18:03
Lookslike your sight moves fine, which can only mean one thing, teh shooter. Your freinds shot it at one extreme, as well as the other, and had teh same no change on POI?

YUP. Made all kinds of adjustments, no change at all.

bigdough666
01-27-2011, 18:18
ETA: Are you sure that's a YHM sight? Retention knob know looks like nothing I've ever seen on their stuff. Also, haven't seen a sight like that on their website.

Im actually not. I know the front is for sure, figured they were a matching pair. I bought the upper with the sights on it already. :wavey:

Flashbang1063
01-27-2011, 19:45
I gotta' say...it isn't even my AR and I'm going crazy trying to figure this one out.

What brand upper are you running?

Maybe...not sure if this would cause no shift in your POI when adjusting your rear sight, but maybe the front sight is slightly canted.

Did you assemble it yourself? Maybe the barrel is over/under torqued causing the entire barrel to be off?

StevieJ
01-27-2011, 19:48
It almost appears as though it isn't mounting directly on the middle of the rail.

DeltaNu1142
01-27-2011, 19:53
That makes no sense.

I believe you're absolutely sincere in your post, but looking at your fifth photo, given no other changes, I'll bet Dr. Kenneth Noisewater that I'd hit the opposite side of the paper if I moved the rear sight to the other extreme.

MisterPX
01-27-2011, 19:54
YUP. Made all kinds of adjustments, no change at all.

Now this is getting freeky deeky weird. A rear sight shift of a 1/4 inch shooting at 25M sould have a profound impact on the POI.


ETA: since I didn't see it mentioned, how big were your shot groups at 25?

DeltaNu1142
01-27-2011, 19:58
It almost appears as though it isn't mounting directly on the middle of the rail.
I know what you're saying, but it looks close enough to me:

http://i.imgur.com/KJqhF.jpg

...and even so, whether the sight's centered or not, moving from left lock to right should make some difference on POI at 5 yards, let alone 25.

jdavionic
01-27-2011, 20:03
Do you have access to a bore laser sighter? Granted it's not what you'd use to sight in the rifle completely, but it would help in getting you close and seeing whether the sight is truly that off.

bigdough666
01-27-2011, 21:43
I gotta' say...it isn't even my AR and I'm going crazy trying to figure this one out.

What brand upper are you running?

Maybe...not sure if this would cause no shift in your POI when adjusting your rear sight, but maybe the front sight is slightly canted.

Did you assemble it yourself? Maybe the barrel is over/under torqued causing the entire barrel to be off?

Upper is from Model 1 sales. I know, not a Noveske or anything but Ive seen plenty of people have good luck with them.

I thought about the front sight being canted, which is why I am considering buying a brand new set, front and rear.

I did not assemble the upper myself.

Now this is getting freeky deeky weird. A rear sight shift of a 1/4 inch shooting at 25M sould have a profound impact on the POI.


ETA: since I didn't see it mentioned, how big were your shot groups at 25?

Yea freaking me out too.

The group was nothing impressive, 1-2". I was more concerned about why the hell I couldnt adjust it then concentrating on making better shots.

Do you have access to a bore laser sighter? Granted it's not what you'd use to sight in the rifle completely, but it would help in getting you close and seeing whether the sight is truly that off.

What I am going to try next. Just wanted to see if I could narrow it down some before.


Thanks for the replys guys, keep em coming. I will keep this thread updated as I make progress. Sux to have such a nice looking rifle and not be able to hit a damn thing with it. :dunno:

Flashbang1063
01-28-2011, 06:41
Upper is from Model 1 sales. I know, not a Noveske or anything but Ive seen plenty of people have good luck with them.

I thought about the front sight being canted, which is why I am considering buying a brand new set, front and rear.

I did not assemble the upper myself.

The more I think about it, the more I think that your front sight is canted or even the barrel was not properly torqued from the factory which will cause the barrel to cant. Are your barrel feed ramps lined up with your uppers feed ramps?

No matter who manufactured the upper, sometimes something slips past QC. I was just asking because I have heard that Bushmaster had some problems with canted front sights at one point.

Good luck troubleshooting and I hope you get it squared away soon.

farmer2
01-28-2011, 07:06
good luck

GenoTac Ind.
01-28-2011, 07:52
That's a UTG rear flip up...I guess get another rear sight and see if there is still a problem.

cowboy1964
01-28-2011, 12:01
Yeah, get a $30 bore laser and at least you can experiment much easier.

What kind of front sight is it? From the pic it kind of looks like my Daniel Defense.

Even if the front sight is canted moving the rear sight WILL move the POI. My front sight is canted every so slightly to the right and I have to crank my rear sight over about 80-90% of the way but I can definitely move POI by moving the rear sight.