PSA 20" AR-10, Terrible Accuracy

[Insanatrix]

Let me preface by saying that I've just been getting into shooting in general and long range precision shooting has always interested me so my issue's could simply be me and over-expectation of the rifle.

Just bought a separate lower and upper from Palmetto State Armory and recently took it to the range and I'm getting pretty bad accuracy at 100yds. I'm looking at groupings that span an entire 12" circular target around the outside and inside, Extremely erratic groupings. My other rifle is a Ruger Precision in 6.5 creedmoor that I can shoot 1-2 moa with out to 300yds easily and haven't tried any farther yet. I'm really thinking either something is wrong with the rifle or the optic. Optic is a Vortex Diamondback Tactical 6-24x50 FFP. I'm going to try putting mbus ironsights on it to eliminate the optic next time I shoot it. Wondering if I should I take the rifle to my local gunsmith and have them look at it? What all could be wrong with it?

 

[hafejd30]

Your optic could be crapped out. But I wouldn’t duplicate results with irons. Mount up a scope you trust and try again.

Beyond that get ahold of someone with a bore scope

 

[LeadZeke]

Mount optic on the RPR. If it runs well you know it isn't the optic. Then remount it to the PSA and be sure the mount is 100% secure. If the problem persists then it is the rifle. PSA is not known for making things that are terribly accurate, so 4moa wouldn't surprise me. 12in at 100y though is a bit much. If you can first thing to check is the barrel nut tightness, sometimes they go way overboard.

 

[hlee]

What ammo? Federal fusion shot like that from my DPMS lr308. Hornady match and Federal GMM both shoot sub moa.

 

[Tim_WNC]

Did you get the upper with an A2 front sight base? or free floated hand guard?

I picked up one of their 18" free float uppers and a lower last fall to use as a hunting rig. AFTER I replaced the POS stock trigger it's a solid 1-1.5MOA rifle (4x optic) with hunting ammo and right at or just under 1MOA with 168 FGMM.

For the ~$500 I have into it, plus whatever I paid for the CMC 3.5# trigger, I'm happy with 1-1.5MOA for deer and pigs. They're availabe even cheaper now.

 

[cornhusker86]

Before giving up on the scope, make sure it's mounted correctly.



If that fails, send it back to Vortex.

 

[garandman]

I know I expect too much from semi auto accuracy.

ETA: By that I mean bolt gun accuracy (under half inch groups ) when I whould just be happy with 0.40 - 0.80" groups

 

[goosed]

Let me preface by saying that I've just been getting into shooting in general and long range precision shooting has always interested me so my issue's could simply be me and over-expectation of the rifle.

Just bought a separate lower and upper from Palmetto State Armory and recently took it to the range and I'm getting pretty bad accuracy at 100yds. I'm looking at groupings that span an entire 12" circular target around the outside and inside, Extremely erratic groupings. My other rifle is a Ruger Precision in 6.5 creedmoor that I can shoot 1-2 moa with out to 300yds easily and haven't tried any farther yet. I'm really thinking either something is wrong with the rifle or the optic. Optic is a Vortex Diamondback Tactical 6-24x50 FFP. I'm going to try putting mbus ironsights on it to eliminate the optic next time I shoot it. Wondering if I should I take the rifle to my local gunsmith and have them look at it? What all could be wrong with it?

12" spread is extreme even for a budget PSA build.

Could be lots of things...

Could be ammo used
Could be your first experience behind a large frame AR? Not following through during entire recoil impulse?
Scope rings/mount not tightened properly (used torque wrench?)
Scope is moving inside rings(scratches on scope body)
Scope rings/mount wasn't pushed forward on rail while mounted
Scope is bad
Picatinny rail is out of spec
Barrel nut not torqued correctly
Brass shows signs the system isn't running properly
Barrel is bad


Start with the things that are lowest cost and easiest to check. Work your way down the list of variables. Let us know your findings.

If you have MBUS on hand I see no reason you couldn't try them. I just wouldn't go out and purchase them just yet. As others suggested it only takes a few minutes to move the optic to the RPR and that will give you a known base line. Though I would likely go with verifying the torque on all the scope ring/mount screws first to see if you missed something or something doesn't feel right. If everything is tight I would loosen and torque it all down again anyways as it's cheap and easy before moving it to the RPR.

 

[Juggerxxx]

I went the same route and picked up the lower one month and the 20” upper another month from PSA. Mine actually shoot very well for my expectations form a semi auto. I mostly shoot bolt actions. It had a few hiccups on double feeding but ended up being a gas adjustment. Below is a target before and after trueing and glueing. As you can see there isn’t much difference so it seems to be a keeper for the most part. I bought my PSA because I witnessed two other PSA rifles shooting sub MOA groups at my range. The 12” groups you are getting are very odd. I would absolutely mount another optic and verify nothing is touching the barrel. I don’t think it is the ammo but try something else too.
After cleaning my barrel for the first time I’m now getting very surprising smaller groups. Anything is possible but definitely give the PSA a fair shake.

 

[Insanatrix]

When I shoot I don't typically flinch or move especially behind a rifle. I'm a bigger guy and the recoil has never really bothered me much, I find it kind of fun.

I'll swap optics from the RPR and see if I get the same results. I use a torque wrench on my scope installs and bubble levels to get them true. The scope is brand new, bought it for this build. I was using 147g ball ammo and bought a box of 150g Remington UMC which was the only .308 they had at the range for me to try and see if it was the ammo. It performed exactly the same. I'm gonna buy some match ammo next time and try it. The scope is brand new, bought it for this build. It's the free floated M-LOK hand guard and nothing moves or rattles on the rifle if I shake it except for where the upper and lower mate there's very tiny movement. Brass looked fine and out of about 180 rounds that I fired I had no FTF or FTE's. The lower has their EPT trigger in it which I don't know if it's good or not. It feels OK and the pull and break on it don't feel too gritty or ungodly. It's my first time with PSA and I wanted to try a budget AR-10 build.

 

[Kickin45]

Please keep us updated as I just purchased the lower/upper separate combo myself. Had to do it before the stupid WA state laws go into effect. They won’t really affect me, but I’m not taking any chances with them twisting their new laws to say and do whatever they please.

 

[bfoosh006]

Make sure the barrel nut is tight, muzzle device tight ...( for that matter check every thing over.) ... there is no reason you shouldn't be getting at least 2 MOA'ish with your fresh barrel and decent ammo.

 

[garandman]

I was building THIS in 223 as a budget AR. I had gotten a cheapie, lightweight AR Stoner barrel (Midway USA) and was getting near 5" groups with bulk ammo.

Replaced the barrel and now getting 1-2" groups @ 100y with bulk ammo. Sometime "cheap" can be expensive. The barrel is not a good place to "save money."

 

[garandman]

Optic is a Vortex Diamondback Tactical 6-24x50 FFP.

Just sent my Vorex Viper red dot in for warranty.

They replaced it no questions asked.

 

[hafejd30]

What twist is your upper? It’s possible the lightweights just don’t shoot/stabilize well.

Look at your crown and make sure there isn’t a ding where the bullet leaves the muzzle.

I’ve owned 3 vortex scopes. 1 HS and 2 pst vipers. The HS and 1 6-24 viper both failed and had to be sent back. So there is a good chance the scope may be the culprit. The PST came broke in my case. HS went down after 50 rounds of 308

 

[BoilerUP]

I was using 147g ball ammo and bought a box of 150g Remington UMC which was the only .308 they had at the range for me to try and see if it was the ammo. It performed exactly the same.

"There's yer problem, right there."

Try Federal Gold Medal Match 175gr; grab a box of 168s too. Also try Hornady Match 168gr ELD-M.

I'm all but certain they'll shoot better than FMJ garbage, and you'll likely find one of the three shoots 'best'.

 

[garandman]

"There's yer problem, right there."

Try Federal Gold Medal Match 175gr; grab a box of 168s too. Also try Hornady Match 168gr ELD-M.

I'm all but certain they'll shoot better than FMJ garbage, and you'll likely find one of the three shoots 'best'.

Any modern rifle that shoots 12" groups at a 100 yd is not merely an ammo problem. I have shotguns that will shoot a tighter pattern. Lol

You should not have to buy FGMM ammo in order to get 2" groups at a 100 yd.

 

[Insanatrix]

Went to take the scope off to swap out for another and noticed that there were scratch marks on the bottom. I guess that the ball area of the scope, under the turrets, was binding on the Leupold scope mount arm as it comes up into the ring. It's not flat but kind of diagonal and it was making contact enough to scratch and move the scope around on every shot is my guess. I moved it so it has more clearance and took it to the range and it was shooting 1/4 moa at 25yds. I did use some Aguila 150g BTHP's instead of the FMJ's but I really think that it was the scope binding in the mount. I'm just glad it wasn't anything super serious or expensive. When I can get back out to our big outdoor range I'll try it at farther distances. I appreciate all the help and suggestions!

 

[goosed]

Went to take the scope off to swap out for another and noticed that there were scratch marks on the bottom. I guess that the ball area of the scope, under the turrets, was binding on the Leupold scope mount arm as it comes up into the ring. It's not flat but kind of diagonal and it was making contact enough to scratch and move the scope around on every shot is my guess. I moved it so it has more clearance and took it to the range and it was shooting 1/4 moa at 25yds. I did use some Aguila 150g BTHP's instead of the FMJ's but I really think that it was the scope binding in the mount. I'm just glad it wasn't anything super serious or expensive. When I can get back out to our big outdoor range I'll try it at farther distances. I appreciate all the help and suggestions!

That's awesome!

Always nice when it's something simple and doesn't cost anything.

 

[Jefe's Dope]

My groups first time out from my PSA upper/lower running Sierra.

 

[gopherslayer]

My groups are similar to Jefe’s above. Mine are with factory 150gr Deer season xP.

 

[Firegrunt03]

These are

View attachment 7096912View attachment 7096913I went the same route and picked up the lower one month and the 20” upper another month from PSA. Mine actually shoot very well for my expectations form a semi auto. I mostly shoot bolt actions. It had a few hiccups on double feeding but ended up being a gas adjustment. Below is a target before and after trueing and glueing. As you can see there isn’t much difference so it seems to be a keeper for the most part. I bought my PSA because I witnessed two other PSA rifles shooting sub MOA groups at my range. The 12” groups you are getting are very odd. I would absolutely mount another optic and verify nothing is touching the barrel. I don’t think it is the ammo but try something else too.
After cleaning my barrel for the first time I’m now getting very surprising smaller groups. Anything is possible but definitely give the PSA a fair shake. View attachment 7096912

awesome groups sir. i have the Gen 2 308 with 18 inch barrel. Its a 1 moa rifle with handloads mainly 165 soft points for hogs. Could you tell me what truing and gluing you did? Ty in advance

 

[Juggerxxx]

These are

awesome groups sir. i have the Gen 2 308 with 18 inch barrel. Its a 1 moa rifle with handloads mainly 165 soft points for hogs. Could you tell me what truing and gluing you did? Ty in advance

I think this thread had some of that info in it. But I’m not a great source for truing and gluing. https://www.snipershide.com/shootin...before-and-after-psa-65.6943661/#post-7740607

 

[army_eod]

I had one PSA AR. Crap in my view. Get what you pay for.

 

[20072ndsight]

You use a wrench on scopes I use a Driver on mine . My PA10 function 100 percent accuracy varies with ammo and caffeine intake . Sub moa M80 ball 2 to 3 moa do pending on manufacture and lot . I have a 20" heavy barrel ss 4x16 Arken scope with a 20mil riser . Enjoy

 

[rdinak]

Try some quality 168/175 smk.