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New AR 15 build shooting way right
Posted: Tue Jul 07, 2015 8:28 am
by KHickam
Howdy
Last night after receiving a new premium mid length upper from PSA - I put it together on the lower I had built and put on the BUIS UTG sight I had bought for my lady
Any way - taking it out to zero using a good quality ammunition AE 223 55 gr - gun is 1/7 in a 16" barrel.
We fired it off bags while prone - way we zeroed our rifles in the military and even after moving the rear sight almost all the way left it still shoots a bit right
figured it was Denise's trigger control but it shoots right for me too even though it was grouping pretty well - 1/2 to 3/4 inch with a three shot group (also taught in the military)
Wondering if it could be the sight - because my MBUIS sights on basically the same gun shoot center without much adjustment
Suggestions?
Re: New AR 15 build shooting way right
Posted: Tue Jul 07, 2015 9:56 am
by Richbirdhunter
Can she shoot other guns well? Does she have a good cheek weld and the same anchor points? 1:7 twist is very fast, could a heavier bullet help the groups?
Re: New AR 15 build shooting way right
Posted: Tue Jul 07, 2015 10:16 am
by ShootDontTalk
Pretty hard to say without actually seeing the gun, but here are a couple of things to check.
If you have a free floating forend, it may be twisted slightly which can offset the optical path between the rear and front iron sights. This creates a built-in cant. The best way to check this is to put a red dot sight on and see if you have the problem. Ignore the iron sights when doing this.
Out of the dozens of AR's I have worked on, I found one upper which somehow was not machined correctly in the rail area and would shoot right or left no matter what. The only solution would be to return it to PSA and let them see it.
By far the most likely problem I have found is a poorly machined rear sight. If you really look closely, sometimes you can spot these defects. The sight will sit off enter when viewed from the rear. I didn't even bother to look most times. I just kept a spare A3 carry handle that was known to shoot correctly. I think you said you had a UTG rear sight and IIRC that is a very likely candidate.
There are other mechanisms, but off the top of my head these are the most likely. Good luck.
Re: New AR 15 build shooting way right
Posted: Tue Jul 07, 2015 9:24 pm
by KHickam
Richbirdhunter wrote:Can she shoot other guns well? Does she have a good cheek weld and the same anchor points? 1:7 twist is very fast, could a heavier bullet help the groups?
Yes, she shoots my nearly identical AR very well - for as little experience as she has - But I have tons of experience shooting them I had to qualify with them at least annually and most of my career twice a year - I shot expert all but a handful of times over my 20 yr career and at my PPC quailfications I have always scored Expert or Master with them. And it shot way right for me too
Gonna get a new rear sight and see if that helps
Re: New AR 15 build shooting way right
Posted: Wed Jul 08, 2015 2:41 pm
by MeMelYup
KHickam wrote:Richbirdhunter wrote:Can she shoot other guns well? Does she have a good cheek weld and the same anchor points? 1:7 twist is very fast, could a heavier bullet help the groups?
Yes, she shoots my nearly identical AR very well - for as little experience as she has - But I have tons of experience shooting them I had to qualify with them at least annually and most of my career twice a year - I shot expert all but a handful of times over my 20 yr career and at my PPC quailfications I have always scored Expert or Master with them. And it shot way right for me too
Gonna get a new rear sight and see if that helps
Did you try bore sighting it?
Re: New AR 15 build shooting way right
Posted: Wed Jul 08, 2015 4:42 pm
by ShootDontTalk
It's shooting to the right of the bullseye on paper. He is having to crank the rear sight so far to the left that there is no windage travel adjustment for moving the POI any further to the left. Bore sighting won't help. Shooting on paper is just bore sighting with your eye, the sights, bullets, and a target. If I could draw on here, I could demonstrate the problem much more easily.
Re: New AR 15 build shooting way right
Posted: Wed Jul 08, 2015 10:40 pm
by KHickam
With a new Magpul BUIS we were able to get the gun zeroed - we did have to crank it a bit left but not nearly as far as the UTG sight

Re: New AR 15 build shooting way right
Posted: Thu Jul 09, 2015 3:56 am
by rbwhatever1
At least it was shooting in the correct political direction. It's a keeper. Glad you got it sighted in!
Re: New AR 15 build shooting way right
Posted: Thu Jul 09, 2015 10:32 am
by ShootDontTalk
AndyC wrote:Is the barrel overtimed, perhaps? I'm not an AR expert, but I recall a saying from building FALs which referred to installing the barrel:
"If it shoots to the left, it needs more heft - if it shoots to the right, it's too tight"
Absolutely. The front sight could be the offender, except that most AR's today use a free floating barrel arrangement. The front sight is usually on a rail on the free floating handguard so the problem is incorrect alignment of the handguard rather than a barrel problem per se. The original sight base, which is mounted on the barrel itself, and the gas tube arrangement make misalignment more difficult because the gas tube passes through the barrel nut.
To the OP, I'm glad you got it corrected and I steered you straight. I take no credit for the answer. I learned it from another armorer who probably learned from someone else. After I replied to you, I checked my box and low and behold, I have one of the offending rear sights - a UTG. I seem to remember someone saying one time that UTG buys sights that were rejected by other manufacturers. That explains how they can sell them so cheap. Hope she enjoys her new toy.
Re: New AR 15 build shooting way right
Posted: Thu Jul 09, 2015 5:50 pm
by cyphertext
ShootDontTalk wrote: I seem to remember someone saying one time that UTG buys sights that were rejected by other manufacturers. That explains how they can sell them so cheap.
Chalk that up to stupid crap people say on gun forums. UTG does not buy rejects from other manufacturers. They make their sights out of cheaper materials, with a lower quality control. I have one on my .22lr AR... works fine for that purpose, but I zeroed it at 25 yards and leave it alone... I'm not spinning the elevation drum to shoot at known distance ranges or changing for windage.
I don't doubt that the UTG sight was a problem, but it is still possible that the rail on the receiver is a touch out of spec, or just within tolerance. Sometimes you can have several parts that are within tolerance, but by the time you put them together, they just don't work together.
Re: New AR 15 build shooting way right
Posted: Thu Jul 09, 2015 6:34 pm
by ShootDontTalk
cyphertext wrote:ShootDontTalk wrote: I seem to remember someone saying one time that UTG buys sights that were rejected by other manufacturers. That explains how they can sell them so cheap.
Chalk that up to stupid crap people say on gun forums. UTG does not buy rejects from other manufacturers. They make their sights out of cheaper materials, with a lower quality control. I have one on my .22lr AR... works fine for that purpose, but I zeroed it at 25 yards and leave it alone... I'm not spinning the elevation drum to shoot at known distance ranges or changing for windage.
I don't doubt that the UTG sight was a problem, but it is still possible that the rail on the receiver is a touch out of spec, or just within tolerance. Sometimes you can have several parts that are within tolerance, but by the time you put them together, they just don't work together.
I didn't read it on the Internet. I heard it at a workshop for certified Colt armorers. This was probably around 2003-2004. Leapers, who markets/owns UTG, only started manufacturing operations in the USA in 2009. Prior to that UTG imported products from China. I'm glad you have one that works. I have one that is obviously not machined correctly. You can see it by just looking.
You do understand that the geometric difference means the POI will not be as far from the POA at 25 yards as it is at 100 yards and beyond. You may have sufficient windage adjustment at 25 and not have enough at 100 and beyond.
Re: New AR 15 build shooting way right
Posted: Thu Jul 09, 2015 6:39 pm
by KHickam
It shoots better - gun does not have a rail it has MOE furniture and an A frame front sight
Re: New AR 15 build shooting way right
Posted: Fri Jul 10, 2015 11:56 am
by cyphertext
ShootDontTalk wrote:cyphertext wrote:ShootDontTalk wrote: I seem to remember someone saying one time that UTG buys sights that were rejected by other manufacturers. That explains how they can sell them so cheap.
Chalk that up to stupid crap people say on gun forums. UTG does not buy rejects from other manufacturers. They make their sights out of cheaper materials, with a lower quality control. I have one on my .22lr AR... works fine for that purpose, but I zeroed it at 25 yards and leave it alone... I'm not spinning the elevation drum to shoot at known distance ranges or changing for windage.
I don't doubt that the UTG sight was a problem, but it is still possible that the rail on the receiver is a touch out of spec, or just within tolerance. Sometimes you can have several parts that are within tolerance, but by the time you put them together, they just don't work together.
I didn't read it on the Internet. I heard it at a workshop for certified Colt armorers. This was probably around 2003-2004. Leapers, who markets/owns UTG, only started manufacturing operations in the USA in 2009. Prior to that UTG imported products from China. I'm glad you have one that works. I have one that is obviously not machined correctly. You can see it by just looking.
You do understand that the geometric difference means the POI will not be as far from the POA at 25 yards as it is at 100 yards and beyond. You may have sufficient windage adjustment at 25 and not have enough at 100 and beyond.
You and I are on the same page... I do understand, that is why I said it works for my .22 at 25 yards, and once it was zeroed for that distance, I don't mess with it!

UTG makes cheap stuff and before they introduced their pro line, their stuff was a total crapshoot. I didn't doubt the UTG sight was bad, and I am sure you have one that is not machined correctly... I returned one for the same reason.
As far as the UTG buys rejects... ok, you heard it at an armorers workshop, same difference... just another rumor like "Walmart guns are sub-standard"... You said it yourself, they made and imported products from China.
Re: New AR 15 build shooting way right
Posted: Fri Jul 10, 2015 12:00 pm
by cyphertext
KHickam wrote:It shoots better - gun does not have a rail it has MOE furniture and an A frame front sight
If this was to me, I was referring to the rail that is part of your upper, the one where the rear sight is attached. It is possible for that to be out of spec, or within the spec tolerance but enough to require more sight adjustment than usual.