AR15 has pretty bad accuracy?

[Dibbs]

I'm hardly an advocate of AR15 accuracy, so I don't have a dog in this fight.

OTOH, you spent less on an entire
upper than I spend on just a barrel. For that money, (keeping in mind they have to make a profit)
the quality of the build suffered, somewhere on the upper. Offhand, I'd guess it's the barrel, especially
considering how you mention the groups opening up early.

 

[WestKentucky]

I didn’t read many of the responses so I apologize if I’m beating a dead horse here...

Ammo. Cheap ammo is not necessarily bad ammo, and mil ammo is not necessarily good ammo. Try other stuff. Most cheaper guns I have messed with like 62gr bullets a little better, and the cheapo stuff is 55gr. Try different... and try wolf if you can find it. Wolf somehow makes ammo a lot of guns like and it’s cheap.

Upper. Check everything. It should be tight. Handguard... clamshell? Might be loose and/or wobbly. Can impact accuracy if it’s moving.

Sight. Make sure it’s all mounted on the accessory rail of the receiver. Don’t bridge from receiver to handguard, that makes a less stable mounting platform. Check all screws, make sure they are all roughly even on torque. You don’t need gorilla strength, but you do need firm. You can easily strip aluminum so be careful. 2 fingers on an Allen wrench max if you don’t have a small torque wrench.

Bolt Carrier Group. Make sure that there is not a whole lot of motion on the bcg. Fore/aft wiggle should be stopped by the locking lugs but anything loose can cause some erratic behavior. A bolt that’s not square to the chamber puts wierd pressures on the case. Should be of minimal concern, but’s it’s just another thing to check.

Sights again... if all else fails, try a different sight just to rule out the most likely culprits. If one sight shoots like crap and another is good then the sight is the issue. If both shoot like crap the problem is with the upper.

 

[JeffG]

Try some different ammo with different bullet weights. It should shoot better than that. Check all scope mounts, rings etc for tightness. Try a different scope. (parallax) Make sure your barrel nut is correctly indexed. Then contact warranty department, if issues are still present.

 

[crestoncowboy]

Barrel nut was my first guess. Rings/ mount in this case, was my second. Something pretty obvious either way. Most handguns from a rest can do better than 4 inches at 25 yards. Something is moving, and in big numbers, not hundred thousandths of an inch either.

I'm also guessing that the heat didn't make the already bad groups double in size, but the repeated movement likely loosened up whatever the problem was further. I'd guess if you keep shooting the group will continue growing until something fails.
In the hundreds of rifles I've shot ive never seen one shoot that bad (or close) from any kind of stable position. Aks, sks, Ar, G3 etc. No one is going to make a rifle so inaccurate that any common handgun can outshoot it, and stay In business long. Anyone telling you that 4 inches at 25 yards is normal, even with horribly mismatched ammo, is wrong. Like I said I've shot 40 grain v-max through a 1:7 ARs and never seen anything close to that bad. He also never mentioned keyholing. And for groups that bad the bullet holes would look like the papal hat.

No ammo is so bad it will shoot 4 inches at 25 yards in my experience. I think people may have overlooked the ops group/yardage. That or some of you are getting some incredibly bad ammo.

 

[illinoisburt]

Possibly a form issue. The scope is pretty tall so centerline might be over 2-1/2 inches above the bore. You mentioned moving it back to improve the sight picture. Cheek weld on an adjustable buttstock is already iffy. Throw in potential cant and head movement with a large dot sight just might answer it.

 

[crestoncowboy]

I have the same scope on a 6940. The eye relief on 3x is terrible. He likely moved it back because of that. With the illumination off the dot is quite small, so precision out to 100 yards is fairly easy. Also the mount (I assume that's what others are referring to as rings since there are no rings) is much lower than a red dot or scope on a carry handle (remember those way back when? ). Wouldn't matter anyway as far as moa is concerned, I could mount my scope 18 inches above the bore and im still shooting the same group size..... would be a pain to get on target, but wouldn't equate to 20 moa groups. There is a mechanical issue somewhere

Assuming that he is an average shooter and had a good rest,(as most people who just mounted a nearly 1000 dollar scope would) something is badly amiss with the rifle.

 

[Hookeye]

I've had a few AR's, all 16", all 1 in 9 twist and all shot 1" or better at 100 yards.
WW, PMC, Hornady or Black Hills. All 55 gr stuff.
I did run lighter trigger springs on all but one.
And that was off a front bag rest.
Scopes no higher in mag than 7X.
And nothing mounted too high.

I do know one manufacturer of .308 AR's did get a bad batch of bbls 2 yrs ago, and some escaped.
They replaced the bbls on a couple of guns and they were fine after that.
They got burned by a supplier, or so they said.
Definitely knew the affected time span, and admitted to such.

But then the guys that bought them worked for a gun shop. So maybe got insider info. I dunno.

Stuff happens, and usually gets fixed.

 

[illinoisburt]

I have the same scope on a 6940. The eye relief on 3x is terrible. He likely moved it back because of that. With the illumination off the dot is quite small, so precision out to 100 yards is fairly easy. Also the mount (I assume that's what others are referring to as rings since there are no rings) is much lower than a red dot or scope on a carry handle (remember those way back when? ). Wouldn't matter anyway as far as moa is concerned, I could mount my scope 18 inches above the bore and im still shooting the same group size..... would be a pain to get on target, but wouldn't equate to 20 moa groups. There is a mechanical issue somewhere

Assuming that he is an average shooter and had a good rest,(as most people who just mounted a nearly 1000 dollar scope would) something is badly amiss with the rifle.

I wpuld certainly not rule out the rifle having an issue, just adding in other compounding possibilities. Personally I would remove the optic from the rifle and pop on a quick set of low irons to retest and confirm the issue.

* As a huge aside, I would never assume high dollar equipment in any way equates to proficiency, experience, or anything else.

 

[748]

Are you certain that the optic itself isn’t broken? My next step would be to swap that out or test it on a different rifle just as a sanity check.

It's new.
I don't have any homeless scopes or rifles I could move this one over on to.

 

[Bfh_auto]

When you decide to try different ammo, I suggest something with a 77 am if you have an 8 twist upper. Mine doesn't like hornady bullets which makes me .
Definitely check everything first.

 

[748]

My 1:7 Colt barrel shoots 55gr ok, HATES 62gr, is ok with 69gr and absolutely loves 77gr. The 62gr stuff I shot made me think my rifle was bad. It was just horrible.

I will order some 77gr ammo or something in that weight range. I don't think I can buy anything heavier than 68 or 70 locally.

 

[crestoncowboy]

I didn't assume he was a sealdeltareconhrt sniper like many internet folks are. But not many people mount up a 1k scope and lob bullets at 25 yards without a rest or a little shooting background. Plus he mentioned qualifying before and being familiar with the platform. I was only assuming he wasn't standing while drunk wobbling or firing one handed to line the scope up, and even then most could do better than 4 inches at 25 yards. I admit he could have been going through withdrawal shakes and that could almost answer such bad groupings

Also the reticle is etched in the glass so I can't imagine the scope being broken internally causing it. Loose maybe. Or mount not tightening right. But it's not like some red dots that the internal projector deal (no idea what that call it so I'm going with that) could be moving.

If he had said he was getting 6 or 8 inches at 100 yards I could see crown, ammo, uneven barrel pressure, gas port, headspacing, etc coming together as some have mentioned. But 4 inches at 25?...with a rifle..... just think on that distance with a rifle? Without some catastrophic mechanical issue have you ever REALLY seen a rifle shoot that bad. I've worked on and fired many hundreds of rifles from absolutely worn out surplus and lever guns to rimfires and up to high end and have not.

 

[748]

The first thing I thought of as it heated up and started tossing bullets everywhere was the scope mount since I did that before about 20 years ago.

I searched loose ar15 barrel nut on the Internet and it looks like they tend to blow up.
Now if I remember correctly doesn't the gas tube go through the barrel nut? Not allowing it to rotate once the gas tube is installed?

 

[748]

I didn't assume he was a sealdeltareconhrt sniper like many internet folks are. But not many people mount up a 1k scope and lob bullets at 25 yards without a rest or a little shooting background. Plus he mentioned qualifying before and being familiar with the platform. I was only assuming he wasn't standing while drunk wobbling or firing one handed to line the scope up, and even then most could do better than 4 inches at 25 yards. I admit he could have been going through withdrawal shakes and that could almost answer such bad groupings

Also the reticle is etched in the glass so I can't imagine the scope being broken internally causing it. Loose maybe. Or mount not tightening right. But it's not like some red dots that the internal projector deal (no idea what that call it so I'm going with that) could be moving.

If he had said he was getting 6 or 8 inches at 100 yards I could see crown, ammo, uneven barrel pressure, gas port, headspacing, etc coming together as some have mentioned. But 4 inches at 25?...with a rifle..... just think on that distance with a rifle? Without some catastrophic mechanical issue have you ever REALLY seen a rifle shoot that bad. I've worked on and fired many hundreds of rifles from absolutely worn out surplus and lever guns to rimfires and up to high end and have not.

I have qualified really hung over before.
I said the worst in ever did was 44 out of 50, that was it.
I'm getting a headache just thinking about that day.

 

[crestoncowboy]

Yeah the nut can't usually back off. On most common guns there are ears that the tube sets between but on some they could still turn I suppose but ive never seen it. On some they actually run through a hole but not most. If the nut was tightened down but not correct on the barrel, maybe it caught a thread burr, then the barrel could still move slightly I think.

 

[GunnyUSMC]

I picked up a used C7 barreled upper (Like an A1 but with Shell deflector). The barrel nut was only hand tight. The gas tube going through the teeth of the barrel nut was the only thing keeping the barrel nut from coming off.
Whoever used that upper must of had a hard time keeping rounds on paper. It only took a few minutes to get everything right and the rifle is a great shooter.
There are many things that can cause a rifle to shoot bad and most of that has been covered already. What we need to do is sit back and let 748 get back out to the range.
Just keep track of the changes you make, best to only make one change at a time if you wish to find what the problem is.
I keep extra barrels on hand for my ARs, just in case. The problem is that they keep turning into rifles.
Don’t forget that you have a warranty

 

[herrwalther]

Based on the rounds I have shot through my PSA AR, the one I built is more accurate than the M4 I deployed with. I have to test it at longer ranges to be sure.

There have been a lot of good suggestions so far. So next time you go back to the range, bring a pocket notebook to log your range session. Be sure to record ammo brand, weight, lot number, magazine used etc. Anything you might be able to determine the problem. And still contact PSA. If the problem persists, they may be able to help you much more.

 

[Frostbite]

I would usually shoot better, heavier ammo first, but that kind of grouping makes me seriously doubt the optic. Try iron sights if you can.

 

[BigBL87]

I would usually shoot better, heavier ammo first, but that kind of grouping makes me seriously doubt the optic. Try iron sights if you can.

Sounds like he cut the front sight off, so don't think that will be an option.

I cut the A frame off the barrel so I could see the target with my optic, not sure of they would allow me to return it.

 

[MistWolf]

...I searched loose ar15 barrel nut on the Internet and it looks like they tend to blow up...

Say what?!?

Yeah the nut can't usually back off. On most common guns there are ears that the tube sets between but on some they could still turn I suppose but ive never seen it. On some they actually run through a hole but not most. If the nut was tightened down but not correct on the barrel, maybe it caught a thread burr, then the barrel could still move slightly I think.

The nut won't back off, but ARs are all too often sent out the door with the barrel nut under torqued. Loose barrel nuts have been the source of poor precision more than once.

 

[748]

Probably get a barrel wrench and headspace gauges.
I removed the gas tube and tried a loosen the barrel nut with channel locks and a rag. I didn't try very hard to loose it since channel locks aren't even close to the proper tool, just wanted to make sure it was more than finger tight.

 

[d2wing]

I got one of those palmetto state armory 16 inch uppers with parts kit for $260.
The lower is a ruger, not home made plastic or 80%.
The optic is a leopold cqt mark 4.

I take it out to get it on paper at 25yd with M193 type ammo.
First thing I notice is its shooting nearly 2 inch groups at 25 yards. I figure that's kind of bad. But for $260 I can't complain too much.
Then the gun warms up, based on touching hot metal surfaces at work I would say it was around 140F then the groups open up to a solid 4 inches at 25yds.
So from pretty bad to even worse.

The only thing it did right was it fully cycled every shot. No .mil M16A2 I ever shot could say that. I do okay with this this platform, I had always been able to shoot at least 44 out of 50 hits qualifying, twice I got 49 out of 50. I could never get 50 out of 50.

I figure I should give it one more chance. Maybe it just shoots exceptionally bad with 55gr ammo. Try 62 and 70gr ammo.
Allow more cool down time.
Find a smaller mag, do a better rest setup. But I did fine every other time with a 30 round mag. So that might not help much.

If I don't get any improvement with heavier ammo and more cool down I figure possible problems are:
The upper is made of armalite reject parts and the barrel is junk.
It just failed an accuracy test at the factory and got sold cheap to PSA, so it's possibly fixable.
The barrel may have a gas port burr.
The head spacing is messed up.
That's what the AR people I know are saying. Before now I just shot them, not worked on them.
Other?

Options are:
Shelve it get another upper, this is the most likely option for now.

But eventually I will unshelve the upper and do something with it.
Fix it, It seems the upper will at least need a barrel adjustment, if not a new barrel.

Sell it for cheap at a gun show.

What do you think?

I had a similar problem with a PSA. Turned out the PSA bolt, and BCG were out of spec. The BCG or bolt would hang up giving very erratic shots. I tried polishing it but had no luck. I replaced the bolt and BCG with BCM parts and groups tightened up nicely. There are a number of things that have to fit right for an AR to work. I used to think that cheap parts were the same as expensive parts. PSA cured me of that. I don't care how popular they are.

 

[crestoncowboy]

Was yours 4 inches at 25 yards with scope bad. Or just bad.

Not being argumentative but seriously asking. Curious

 

[25-20 WCF]

Was yours 4 inches at 25 yards with scope bad. Or just bad....

Maybe you could clarify just what you are asking. I have no idea.


.

 

[crestoncowboy]

The op said his scoped and presumably rested rifle was shooting at 4 inch groups at 25 yards. (So 16 inch minimum at 100.) I have never seen a rifle shoot that poorly from a minor issue. I was simply asking If yours was that bad. I can only think of a couple things that could cause groups that bad.

ETA I was asking d2wing if his was that bad. He had mentioned previous experience with a bad bolt carrier. I didn't know how to quote, I couldn't get it to work. Sorry for the confusion