Having trouble with the iron sights

Discussion in 'AR-15 Discussion' started by TheSadPanda, Sep 1, 2011.

  1. TheSadPanda

    TheSadPanda New Member

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    I recently purchased a new SIG M400 AR and put on a magpul BUIS, but kept the front post on. So naturally I want to sight the irons in before I get a red dot, but I just simply can't do it. In order to sight in you have to get a grouping to move around. I cant get anything even close to a group. heck, @ 50yds I'm not even on the paper half of the time. I'd swear I'm in the correct sight position, and I'm not anticipating recoil. So does anybody know what I could possibly be doing wrong, and how I could fix it? :eek:
     
  2. Snakedriver

    Snakedriver New Member

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    If your SIG AR is shooting all over the place like that at 50 yards, something is way loose. No way it should be like that. Check to make sure that everything is tightened properly, but don't over torque anything. Is the MBUS throughbolt centered and seated in the rearmost notch/slot on your flat top? Also, what ammo are you shooting? The wrong ammo can cause wild shots depending on your barrel.

    Try moving closer to the target, to say at 25 yards to get a better idea of where you are shooting. The front sight is adjustable for elevation (vertical), the rear MBUS sight will only be adjustable for windage (horizontal). Adjust one direction at a time starting with the vertical. Once you get the vertical point of impact to agree with your point of aim, adjust the horizontal impact to bring it into agreement with your point of aim. That should give you a pretty good zero.

    A picture of your set-up may be helpful too.
     

  3. Sniper03

    Sniper03 Supporting Member Supporter

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    Panda,

    If you can be a little more precise about what is happening on the target. Example hitting high most of the time, low most of the time, or shot group is Just all over the place left and right, high and low.
    It is a 1:7 twist rifle so it should not be the effect of barrel twist. Just let us know! What ammunition are you shooting Brand and Grain, reload or factory. Could be a problem with assembly. Like a loose barrel nut or a bad barrel. It happens!

    03
     
  4. TheSadPanda

    TheSadPanda New Member

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    I'm just uploading these pics right before work. I understand how the basic sighting in process goes, but I just can't seem to get any consistency. could it have anything to do with lubing or lack there of? I'm shooting american eagle .223 55 gr. The shots are just everywhere. I have literally no set direction im off by. It could very easily be me as well as the gun I think.

    IMAG0209.jpg

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  5. Sniper03

    Sniper03 Supporting Member Supporter

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    Panda,
    Do you have any other rifles with iron sights. Just for kicks you might shoot it to see if you are having the same problems. If you are it is something that you are doing. If you shoot it well then we need to start looking at the weapon. The American Eagle FMJs are good training and practice ammunition. In fact on the SWAT Team we used them for training and the shot equally as well as our standard operations ammunition which is rare when you switch to training rounds due to cost. The other thing you might do is if you are going to get an optic go ahead and get it and install it. Get it sighted in. If you have no problems then we are back to something going on with the iron sights or maybe how you are looking through them. I know the BUIS is designed to have a large rear aperture since they were designed for CQB. In my case my eyes are not what they use to be. So sometimes I have difficulty seeing the irons that well anymore. And the fact that the BUIS has a large hole (Aperture) in the rear sight this might add to the problem. The only thing that throws me is the 50 yard distance? And missing the target completely. How big is the target you are using. Just some ideas! We will be here to help. Shoot it off of a rest to check for accuracy.

    03
     
  6. Jpyle

    Jpyle New Member

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    Are you shooting off-hand or from a rest? Do you have the rear sight set to the proper aperture? Is the front sight indexed properly, sight post tight (not wobbly in base).

    Have you tried use a bore sight laser to align the sights before trying to zero?
     
  7. TheSadPanda

    TheSadPanda New Member

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    I wont be able to afford a red dot until the end of the year, so im kind of stuck with the iron sights :( the BUIS has the dual apertures (small and big) and ive tried both with almost the exact same results. The tagets are the standard 10 or 12" circles. Ironically, my only other rifle with iron sights was so bad from the factory that i can visually see how crooked the back sight is. I shoot handguns just fine with regular sights.

    Ps- im sorry for any spelling errors, im writing this on my phone.
     
  8. FCross7

    FCross7 New Member

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    I would let someone else, maybe someone who works at the range, shoot the rifle and see if they get the same results. That way you can at least narrow it down to either you or the rifle. If it does turn out to be the rifle, I'd give SIG a call and see what they have to say.

    -Fred
     
  9. Quentin

    Quentin New Member

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    Panda, have you tried shooting from a sandbag or other rest like JPyle mentioned? If you haven't yet try it starting out at 25 yards. You should be on the paper and be able to group. Oh, how's your eyesight, if the sights are blurry it's hard to get a good group shooting offhand.
     
  10. TheSadPanda

    TheSadPanda New Member

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    Im not sure who else i could get to fire the rifle that knows what theyre doing. But ill see what i can do, because its definitely worth knowing if its me or the rifle. I did all this shooting from a bench with the front rested on a black with my hand in between. My eyesight is almost perfect. Im forced to shoot rifles with my non-dominant eye, but its never been a problem for me before.
     
  11. Quentin

    Quentin New Member

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    I'm left eye dominant and shoot long guns from the right side, never has mattered before so I doubt that's your problem. With a pistol I do fudge over and use the left eye.

    Really sounds like something could be loose. Too bad you're having trouble finding someone else to test it. That's the best test. Or you could borrow a scope or red dot but then that wouldn't test your irons.
     
  12. TheSadPanda

    TheSadPanda New Member

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    Thats EXACTLY what i do. I could put a scope on, but id have to buy new rings because none of my others can see over the front post. Is there any way to see if anything is loose?
     
  13. TheSadPanda

    TheSadPanda New Member

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    I went to the range todayto try again with my AR and luckily i got some very definitive results. I shot at 25 yds and agaaun tried both small and large apertures. I found that with the large aperture i always was on paper, but shot rather spiratically. With the small aperture, i had great groups to adjust from and sighted it in perfectly at 25. I really concentrated on my breathing and trigger pull today, and i shot a lot better because of it. This makes it pretty obvious that the problems i hd shooting yesterday were definitely my fault. Thank you for everybodys help. If anybody would like i can post pictures of y targets from today to show how much better things were.