Trouble Zeroing my BUIS

[senorlinc]

took my rifle to the range this weekend to zero my aimpoint. i know step one is zero the irons. i have a troy BUIS and the standard AR FSB. couldnt get it on the paper at 50m so moved it in to 25m. was low and way right. got the elevation corrected however was unable to move the group left even after cranking the rear peep almost all the way to the left. consulted ex-.mil guy and he too was perplexed ....what am i doing wrong (i know it has to be me)
FWIW its a 16" noveske bbl, 1/7 twist, used both brass and wolf 55gr ammo

[MisterWilson]

Are the sights on tight?

Is there any wobble to the barrel?

Every conceivable thing good & tight?

With the sights flipped down, does the front sight post appear to be canted?

Did you possibly apply any undue pressure to the barrel?



That's all I've got.

[Iraq Ninja]

You said Noveske barrel, but who built it?

[senorlinc]

Grant built it. doesnt appear to be crooked however i could be wrong.

i poked/prodded and shook. nothing seems loose. i was really thinking operator error but......

[lostwake]

that would be my guess. whenever i have a problem like that i have my friend shoot my gun, and thats almost always the case. see how it shoots with someone else behind it. are you shooting prone? or on a bipod? or sandbag?

[senorlinc]

i did have a friend try it out. we both shot from sandbags at 50m, he lefty and i righty. didnt touch paper. at 25m we were both low and right from the rest. consistant right? not so much. we got elevation worked out but no matter how far we moved the rear left, it shot the same group

[lostwake]

That must be very fustrating. I have trouble sleeping if my weapons arent sighted in. Have you taken the fsb off or done anything? Id like to see a pic of your setup.

[Failure2Stop]

You can also zero "backward" if you are having adjustment issues- sometimes it's a little less frustrating to approach the problem from a different angle instead of continually running into failure after failure.

If possible, bore-sight your optic and iron sights first.
Then zero the optic at your relevant distance.
Once the optic is zeroed adjust your BUIS to meet the optic's aiming point.
Confirm/adjust BUIS zero.

[greene]

I had the exact same problem with the troy rear BUIS on my n4 recce basic.I tried sighting it in at 50 yards and couldnt hit the target. At 25 yards it was about the same experience you had. I checked the front sight base and every thing seemed fine,then put the plastic handguards back on in fear I installed my omega rail incorrectly,same results with the rear sight. So I then put on my larue rear sight and it was almost centered,so I doubt it has anything to do with barrel itself. I doubt that its completely unimaginable that troy could puy out a lemon and thats the conclusion I finally came to.

[Stonerriflefan44]

I had the same issue with a troy buis. I could not get a good zero, I just about had it adjusted all the way to the left and I knew that my rifle, had been sighted in with the factory carry handle. The rifle in question was a de-banned config. Colt MT6400C. ( accept for the FSB & muzzle device, felt no need to change it) I noticed that the slot ( flathead) screw had loosened a bit, causing the rear sight to shift on the upper. Also noticed that it wasn't flush on the receiver. After some minor adjustment, and using the proper screw driver to torque it down. I was able to get it squared away.

Make sure that your buis is torqued down, my first concern was scratching or stripping the slotted screw, so I did not have it tight enough and it shifted on me. IMHO if it were a torx or allen screw would be better. Although a coin( dime ) could be used in the field if an allen wrench is 100 miles away.

[Sudden]

I zeroed my M&P15 this weekend. I wanted to do something quick and easy as it was my first time to the range with the AR. I zeroed at 25 yards. It was hitting about 6 inches high and one inch to the left. Several turns of the front sight and a couple of clicks on the rear sight and it was in good. This was with Troy BUIS sights I had attached just the day before. I hope to get back each weekend to check the zero at new distances. The range has 25, 50, and 100 yards. I can tell you I like this rifle much more than I ever dreamed I would.

[stormblue]

This thread has opened my eyes.
I've had some problems with rifles needing more windage than I'd like.
I assumed it wasn't the rear BUIS. After all I've never read a bad thing about this manufactures sights. I just mounted 4 rear sights on a rail. The variance between sights would explain why I need 20 clicks of windage on some rifles. And to think I've taken a hammer to a couple of front sights when I should have blamed the rear. I need to get rid of that hammer. :D

[EZRider]

Has anyone ever tried a laser bore sight to start your zero prcedure? I thought I might try that on s new set of mbuis