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problems with AR-15 accuracy

atilla

atilla

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i've been fighting with my .223 AR for months to get it to shoot a decent group. for whatever reason it just can't do it. it's been in the following configurations:

A1 upper, iron sights.
A1 upper, carry handle mounted comp ML2.
A3 upper, iron sights on detachable carry handle.
A3 upper, comp ML2 in larue cantilever mount.

i can bring the groups in a little tighter with iron sights but they are still horrendous. the groups suck proned out (prone unsupported) on the ground, they suck standing, they suck kneeling, and they suck in a supported position at a bench. i was able to zero my 9mm AR with around 16 rounds and i had the thing shooting dead on on a 300 yard simulated target.

the only common denominator here is the barrel. the A3 upper is brand new, the lower is not brand new but it was never assembled into a complete rifle--but the barrel was swapped from the A1 to the A3 upper last weekend. headspace appears to be OK. the barrel is the only one i've got and so it was used in both uppers.

is there anything i can look at when it comes to the barrel that would be a glaring HEY SOMETHING'S NOT RIGHT HERE. i am ready to just get a new barrel (new delta ring while i am at it... the finish is worn on it) but i am also just as ready to take this thing and cut it up into a bunch of tiny little pieces.

thanks guys.
 
it's a 1/9 twist, .223 chamber, 16" long.

i've used: ultramax reloads, remington UMC, JHP varmint rounds, JSP express rifle rounds, privi partizan. same results all across the board with any ammo type.
 
atilla said:
it's a 1/9 twist, .223 chamber, 16" long.

i've used: ultramax reloads, remington UMC, JHP varmint rounds, JSP express rifle rounds, privi partizan. same results all across the board with any ammo type.
Click to expand...

Well the ultramax and umc can vary a lot for accuracy. The varmint's should be OK, but are usually a bit lighter. I've never heard of the JSP stuff. Privi is supposed to be pretty good though. What are the weights on the bullets? Have you tried 62gr or above yet?

Also, how big are these groups and how far away is the target?
 
i think the box of privi that i got from PSS was the 62 gr... same effect as all the other rounds.

the rifle is just awful--i cannot hit a 3" flourescent target spot at 25 yards standing or kneeling. it's that bad.

as far as weight on everything else: the ultramax is 55, as is UMC, winchester was 45, according to remington the stuff which i shot today was also 62 gr.
 
Some things you could check in the barrel are wear and fouling. Does the gun shoot better after you clean it and does it get abnormally worse the longer you shoot? Also, check the condition of the muzzle crown, it doesn't take much to damage the crown and cause accuracy problems. If damage is visible, the barrel can be re-crowned by a gunsmith.

Also, is the fit between the upper(s) and lower tight? Worn out holes for the takedown and pivot pins or poor fit could cause some play resulting in poor accuracy. Popping in an accuwedge might help here.

Good luck.
 
supermoto: done and done. i've given the rifle to several people at the range but we can't nail down exactly what the problem is. one guy was there shooting quarter-sized groups at 100 yards so i think if anyone who fired the rifle would be able to make a shot at 25 yards it would have been him...

kevin: it seems to suck the same whether it's clean or dirty. the fit is pretty good--very tight between the upper and lower. the handguards have a little wobble but even with the originals these issues were present. i'll check out the crown and try to snap a good picture.
 
the barrel came with the A1 upper, it was a complete upper i bought a few months ago from FDF in uxbridge.

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the crown is pretty much something you'd have to look at... my blackberry isn't exactly a SLR. [hmmm]

there's a spot that looks a little suspect but neither my girlfriend or myself can really say for sure that it's not %100 right. the pictures are as good as i could get with my "camera".
 
How was the barrel broken in and what is the round count on it? Sounds like it needs to be replaced.
 
One more question, how are the holes in the paper when you hit it? Are they round and look like a 223 hole, or oblong, or just plain weird looking?
 
no clue about the round count and they didn't know at the shop unfortunately.

the holes for the most part do look like regular old .223 holes, in terms of .22 diameter holes some seem a bit more ragged than my 10/22 or mosquito but .22LR to .223 rem is a poor comparison i think. i haven't seen anything that's really obvious like a keyhole hit or anything.

i really don't want to have to replace the barrel but if i have to do it i don't have much of a choice. would the crown being jacked up cause keyhole hits?
 
atilla said:
i really don't want to have to replace the barrel but if i have to do it i don't have much of a choice. would the crown being jacked up cause keyhole hits?
Click to expand...

Keyholing is caused by a lot of things. The crown being jacked could be one. I had an issue with a flash suppressor that had a burr in it, took it off and no more problems. Put another flash suppressor on it and no problem either. But the most common is the bullet being too light relative to the rifling. With a 1/9 twist, I would look at using a 69 grain bullet if you are going for dead nuts accuracy and grouping.
 
at this point i just want to be able to effectively put rounds downrange on target and i've been unable to do that. i can walk shots all around a target but every time i get close to the center the rifle changes it's mind and the rounds go somewhere else entirely.

i adjusted the aimpoint something like an inch to the right yet the shots stayed in exactly the same spot. this is par for the course no matter what i'm using to aim with or who is shooting the rifle.
 
go to the range, bench it supported on both ends, shoot a group. Get a friend to come along with another upper, switch out uppers, shoot another group. My guess is you have a barrel issue, maybe chamber, but it could also be the bolt not fully seating. Eliminate one variable at a time until you nail it.

If you want I'll come over with my spikes/stag m4 upper to try on your lower, let me know.
 
Is it a light or a heavy barrel? You said it was swapped from an A-1, that means it's probably light and that can make a lot of difference right there. Forget the headspace and all that, if the headspace was off that much you'd know it more then bad accuracy. The standard military version M-16A2, on average, is good for about a 1-3 MOA at 100 yards. Meaning under ideal conditions with a good shooter, it will shoot average groups of 1-3 inches at 100yards. But that's with a heavier barrel then most of your out of the box AR's come with, and probably yours.

Plus, factor in shooter error and you might have a case for a heavier barrel and more snapping in time. Just kidding...[wink]

You should try to zero it at 25 yards, prone, and rested if possible. Just my humble opinion.
 
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at my range there's no way to shoot too comfortably at the rifle side at 25 yards because you're pretty much halfway down the 50 yard range and especially yesterday it would have been like going out in your wet front yard and rolling around.

on the barrel: it's a pencil barrel, it's definitely not heavy at all.
 
atilla said:
at my range there's no way to shoot too comfortably at the rifle side at 25 yards because you're pretty much halfway down the 50 yard range and especially yesterday it would have been like going out in your wet front yard and rolling around.

on the barrel: it's a pencil barrel, it's definitely not heavy at all.
Click to expand...

Can't go to the target, I know those set-ups -- bring the target to you.

Get a target stand and put it 25 yards away from you. That you should be able to do.

Get a heavy barrel, that's step one. Can't ask for accuracy from a weapon that's not that accurate. ;)

On another subject,,, no to be Mr. knowitallonline guy .. but have you ever tried an isosceles shooting stances instead of that cup and saucer/weaver you're using in that pic/avatar, assuming that picture is you?

Take a look at this video...http://www.ehow.com/video_2359775_take-isosceles-pistol-shooting-stance.html
 
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i haven't but i may try it out in the future--it can't hurt.

tele_mark and i may meet up at the range soon and do the upper swap as well.

it's such a shame that "get a new barrel" is totally easier said than done right now.
 
atilla said:
i haven't but i may try it out in the future--it can't hurt.

tele_mark and i may meet up at the range soon and do the upper swap as well.

it's such a shame that "get a new barrel" is totally easier said than done right now.
Click to expand...


Good luck, spend the money and do it right if you want the right end result.

That position is pretty solid, the guy on that video bashed it a little, but it's okay turn the volume off [smile] -- the triangle that you form creates a very solid position which allows more of your body to absorb the recoil and you can stay on target and deliver follow ups if necessary. Try it. It takes some time to get used to,, ooh and that's still a cool picture, I wasn't busting on that.
 
i wanted to add a foregrip to the rifle for shooting in a position off the bench but it looks like the money will be spent elsewhere. that's what money is for though, isn't it?

i really do like the rifle even if it's been a money pit so far and a pain in the ass when it's not being a money pit. to compare and contrast here my 9mm AR is a great piece. olympic has a bad rap but so far the 9mm rifle has been nothing but good to me.

does anyone have any leads as to where i might be able to find a 16" heavy barrel that i won't have to wait 3-4 months for? [laugh]
 
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considering i only bought the upper last weekend and swapped in the A1 barrel i don't want to go out and buy a whole new one so soon, it's a BCM anyway so that's good.

if i could re-use the gas tube, front sight/gas block, and the handguard cap that would be great as there's nothing wrong with those. i would like to get a new delta ring assembly but that's not really a huge deal at the moment.
 
thanks wookie, supermoto, and stef--some great places to start for me.

would it be a huge PITA to re-use the parts off my A1 barrel?

edit: there are a few barrels i'm looking at that rainier arms has in stock:

WOA match grade SS 16" wylde chamber: http://www.rainierarms.com/?page=shop/detail&product_id=600

YHM chrome lined parkerized 16" 5.56 chamber: http://www.rainierarms.com/?page=shop/detail&product_id=1505

daniel defense chrome lined parkerized 16" 5.56 chamber: http://www.rainierarms.com/?page=shop/detail&product_id=1495

i do not really need the rifle to be a tack driver as i could always buy a bolt-action rifle for long distance shooting. i DO want the thing to put down decent groups at 50 yards, i want a rifle that will shoot like any other AR. in all honesty i am leaning towards the YHM barrel because it's well within my budget and people seem to be pleased with the quality of YHM parts.

one thing that i am curious about when it comes to re-using the front sight/gas block is that all the stuff i have referenced mentions roll pins that hold the gas block on to the barrel but on mine these are not present. there are two holes but they are empty, the only pin is the gas tube roll pin--what's up with that?
 
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atilla said:
one thing that i am curious about when it comes to re-using the front sight/gas block is that all the stuff i have referenced mentions roll pins that hold the gas block on to the barrel but on mine these are not present. there are two holes but they are empty, the only pin is the gas tube roll pin--what's up with that?
Click to expand...

There should be 2 taper pins holding the front sight base onto the barrel. Part 7, here:

colt-frontsightassembly.gif


Gas blocks (instead of front sight bases) are attached differently - varies with each manufacturer. Which is yours?

Without the taper pins, the front sight and the gas system is only being held in place by the gas tube roll pin, and whatever friction/corrosion is between the front sight and barrel. Since you tried both iron sights and optics, I'm at a loss to explain how the lack of those 2 pins are causing your group issues. I suppose if the gas system wasn't working because of misalignment it would cause problems, but I would expect reliability to suffer, not accuracy.

Still, if it were me, I'd replace the taper pins and try it again before I spent money on a new barrel. I'd hate to find out that $10 in parts was the problem, unless I was looking for an excuse to buy that YHM. I believe you said you got this used - do the taper pin holes in the FSB line up with the holes in the barrel? You never know what a previous owner tried to do - tried to remove the FSB and failed, removed the FSB and replaced with a used one and didn't install the pins; there are a lot of bad possibilities in there.
 
yeah, there are zero taper pins on the front sight assembly. i have had zero reliability issues with the rifle. so far it has gone bang every time it was supposed to.

everything looks like it lines up OK with the pins... i can see straight through the assembly. if anything the i was able to get slightly better groupings using iron sights but i think i also threw in a bit of kentucky windage on that as well.

i think that i may buy a new gas block and front sight combo if i get the new barrel... i kind of have my heart set on the YHM flip-up one. i definitely do not want to use the one on this barrel if it's this jacked up. i may just order the parts anyway even before i get out to the range with other uppers. worst case scenario i suck at shooting for some reason (doubtful considering how jacked up the groups are) and i have parts to build the NES lower when it comes in. [laugh]

edit: forgot to mention but to the best of my knowledge everything on the A1 upper was DPMS. there are also some marks around where the taper pins SHOULD be.
 
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