While at the range last week I figured I would actually try and get my ARMS BUIS sighted in. After I got done I was hitting clay targets at 100 yards. This is plenty accurate enough for me but in order to get it zeroed at 100 yards I had to turn the front sight post up so far it is sticking out of the top of the protector.

I'm not sure this is normal but I'm think that is not.

The rifle is a 16" flat top carbine upper, I'm not sure which model ARMS BUIS it is. I was using generic 55gr ammo. This was putting the front sight post in the middle of the rear sight hole and the top of the sight post on the middle of the target.

Pics of the front sight, and the BUIS sight.

http://www.pirate4x4.com/forum/picture.php?albumid=290&pictureid=3239

http://www.pirate4x4.com/forum/picture.php?albumid=290&pictureid=3240

http://www.pirate4x4.com/forum/picture.php?albumid=290&pictureid=3241

http://www.pirate4x4.com/forum/picture.php?albumid=290&pictureid=3242

Luke

you need the taller front sight post. i think the flat top uppers are supposed to have a taller front sight post than the a1 and a2.

edit: after looking at mine, i think you have something else going on. my fsp is way bellow the top of the ears on the front sight. maybe there were two heights of front sight towers. i can't remember now if it was the tower of post that was taller.

you need the taller front sight post. i think the flat top uppers are supposed to have a taller front sight post than the a1 and a2.

edit: after looking at mine, i think you have something else going on. my fsp is way bellow the top of the ears on the front sight.

The upper is a complete Stag flat top upper, that I bought used. The sight post was much lower then it is now when I got it. I would imagine that Stag put the correct height sight post in it.

That is why I think the problem is with the rear sight.

Luke

are you using the 0-200 aperture?

I guess I'm not sure what the range is on the aperture but I can take a pic to show you what it looks like:D

I'm looking through the hole not the notch.

http://www.pirate4x4.com/forum/picture.php?albumid=290&pictureid=3243

Luke

The problem is in the FSB...it is most likely not "F" height. There are two different heights of FSBs,the lower one is for fixed carry handles and the taller "F" FSBs for detachable handles and detachable BUIS.

The problem is in the FSB...it is most likely not "F" height. There are two different heights of FSBs,the lower one is for fixed carry handles and the taller "F" FSBs for detachable handles and detachable BUIS.

I just looked and it is marked "F". I was told upper was bought as a complete Stag flat top upper.

Luke

Just got off the phone with ARMS and Stag.

The guy at ARMS said the small aperture should zero fine at 100 yards. He said I could send the sight back and they will check it out.

The guy at Stag is e-mailing me a prepaid shipping label to send the upper back. He thinks the f marked fsb is out of spec.

And that is why I went with the Rock River non flip up sight (the one that is basically a bolt on carry handle rear section).

It has elevation adjustment.

And I have room for an Eotech on the remaining flat top :D

I think with the small aperture, your shots should be high at 100, as it is for a range of hits within a zone from A to B.

Set it for 3" high at 100, or something like that. Should put the front post down a bit. You should be around 1.25" low at 25 yards IIRC.

That's why the sights are so high above the bore, for the "point blank" distance stuff (remember this is to hit people sized targets, at various ranges with coarse settings), it is not set up for head shooting critters with specific fine spot aiming- at least not with the mil spec stuff.

If that doesn't work, then yeah, what those other guys said :)

http://img528.imageshack.us/img528/7343/001kbj.jpg (http://imageshack.us)

Swung by the shop right before closing, somebody had a Bushmaster M4 clone for sale on consignment.

Flat top with BUIS, Trijicon ACOG and Dot Docter, for $2K. Bet it's gone tomorrow. Oh yeah, it had a YHM quad and a ghetto grip (unknown manufacturer- I hate them so didn't check that out).

If you would have bought a larue you wouldn't be having this problem :flipoff2:

If you would have bought a larue you wouldn't be having this problem :flipoff2:

Yum, that kool aid tastes goood.:laughing:

If you would have bought a larue you wouldn't be having this problem :flipoff2:

agreed:flipoff2:

Swung by the shop right before closing, somebody had a Bushmaster M4 clone for sale on consignment.

Flat top with BUIS, Trijicon ACOG and Dot Docter, for $2K. Bet it's gone tomorrow. Oh yeah, it had a YHM quad and a ghetto grip (unknown manufacturer- I hate them so didn't check that out).

That's not a great deal, but it's not too bad either. If you could bargain a few 30 rd mags or something I'd spring for it.

The rifle sold rather quickly.

It had a Swan sleeve too.

One good thing about the economy, some folks are selling stuff at decent, and maybe even crazy low prices.

I got my upper back from Stag today.

I bought this upper used from a guy in NC, the box he gave me had a manufacture of 2006 on it. I told Stag all of this when I called about my problem. They e-mailed me a shipping label to send it in with.

With no questions asked I got a new front sight base, sight post, and a new barrel. The tech on the phone thought the sight base might be out of spec, so I figured I would get a new one but I didn't expect to get a new barrel.

I'm pretty happy with Stags customer service so far, but now I need to go to the range to see if they actually fixed the problem.

Luke

:adds Stag to the list of companies to consider in future:

Thanks for coming back and actually keeping us updated, instead of leaving us with another cliffhanger thread. :)

Well I made it to the range and the problem is fixed. I'm not sure which part had the problem but Stag took care of it.

Luke

Glad to hear they took care of it. I have a AR with Stag receivers and its good to know they are taking care of problems.