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fnogger
July 26, 2017, 15:54
So... I have a little over 100 rounds down the tube of my AR.

I'm not getting very good groups at 100 yards though - 3", maybe a little bigger.

Scope is known good, right off my target build 10/22. Fairly sure about the nut behind the trigger as well - with said 10/22, shooting MOA at 50 yards is doable with decent ammo (SK Std+, etc). Group shot off a concrete bench with bags up front and at butt stock.

Rifle has 20" barrel (not chrome lined), 5.56 chamber, 1:7 twist, A2 muzzle device, and the hand guards are supposed to be free float (Midwest Industries SSM, made for PSA). Trigger is single stage, crisp, but heavy. Gas is rifle length. A2 butt stock.

I've tried Federal 5.56 62grn, 223 55grn FMJ, 223 50grn JHP (all American Eagle from Wally), and Aguila 5.56 62grn and 223. Ammo type didn't seem to affect group size much, although the best of the bunch was the Federa 50grn JHP, but that was still a 3" group at 100 yards.

Questions -

Should I step up in ammo quality? And perhaps bullet weight for that fast twist? Recommend a 70-ish grn match load I can buy (Black Hills,etc?)

Which muzzle device? I know the closed bottom on the A2 can disrupt gas flow, etc - shoudl I just remove it, and shoot bare/get a thread protector?

Rifle seems to lock up tight, but I have to break it in half to fit in my cases. Should I spend the $2 on an "Accuwedge" thing? IIRC it helped with the last AR I owned (back in the early 90s)

Thanks!

SAFN49
July 26, 2017, 17:04
Torque on the bbl nut? If too low can cause accuracy issues.

fnogger
July 26, 2017, 17:20
Torque on the bbl nut? If too low can cause accuracy issues.

I am fairly sure it is in spec. But the spec is fairly wide - 30-80ft/lbs iirc. Is higher better? Or just confirm it is in spec?

OLDMANPBK
July 26, 2017, 17:35
Try some Hornady 69gr Match. Closer to 30 than 80 on the torque. Accu Wedges don't help much. I think you have an ammo problem at this point.

fnogger
July 26, 2017, 17:53
Try some Hornady 69gr Match. Closer to 30 than 80 on the torque. Accu Wedges don't help much. I think you have an ammo problem at this point.

Being a rimfire shooter that was where I was headed first

rowjimmy
July 26, 2017, 18:01
Try some Hornady 69gr Match. Closer to 30 than 80 on the torque. Accu Wedges don't help much. I think you have an ammo problem at this point.

^This

I've shot 1 moa 5 shot groups with 2 moa ammo, but consistency and repeatability is key. That is likely 2 moa ammo at best.

Also, i put together one of PSA's freedom rifles and it was shooting like crap (but it might have been my optic.)

Put a mag or two through it, then put it away and went to the range a week later and it was almost like a tack driver, given the quality of the ammo and rifle. It ay just need a little break in time.

You can get decent accuracy with 55 gr ammo and a 1/7 twist, but it is geared toward heavier bullets.

hueyville
July 27, 2017, 06:25
AccuWedge is a gimmick that makes it harder to open and close your rifle. If you have a rough bore or throat 100 rounds are not enough to smooth it out. I would first continue to shoot it with a variety of ammo and weight bullets to see if settles down. Continue to look for dumb stuff like loose scope ring. Did you lap them? Muzzle device tension will change barrel harmonics more than muzzle device type. I like three prong devices and symmetric devices. TrYing a different muzzle device is a $20 option but would work on admitted heavy trigger. If want will mail you a squared and polished milspec trigger for free if mail me your stock trigger and will do same to it and drop in one of my builds. Easy peasy is drop a JP 3.5 Enhanced Reliability spring kit in and should bring you to four pound pull without light primer strikes and no alteration. If your over 30 ft lbs on barrel nut torque and gas tube is aligned all you can do is screw it up fooling with it. Was upper squared before barrel installed. About one in ten PSA, Anderson, Aero uppers I use out of box are square so if barrel is not straight and in line with bolt then bolt face is not perpendicular to bore so round will have some binding in chamber.

Again, before you tear it apart, lower the trigger pull, try variety of ammo and get more rounds down bore. Some will flip out about this but some barrels have to be lapped to get full accuracy out of them. If after lessen trigger pull and another 200 rounds of ammo would consider squaring upper and running a few Tubbs barrel lapping rounds down bore. On a new barrel, especially a price point I push a patch with copper fouling remover down bore every 10 rounds for first 100 so if any machining burrs get raised up can push them out. People debate barrel break in and if it's necessary or beneficial and post all kinds of test results. I break all mine in, if know rifle is built right and doesn't shoot well in first 500 will at least run a few throat lapping rounds through it. Clean crap out of it without damaging it cleaning improperly and once it starts shooting well can go hundreds of rounds between cleaning. If take muzzle device off examine crown well, it might need lapping as well. Do all the simple stuff first but trying different loads, improving trigger pull and putting rounds down bore will likely get you on track.

TenTea
July 27, 2017, 07:06
So, in a nutshell...
1 - have a good trigger
2 - learn the iron sights
3 - use known good magazines
4 - find best bullet for twist rate
5 - shoot, clean, repeat

I would add:
A - use a good solid rest and rear bag when ammo testing
B - blacken the sights (carbide or aerosol) to enhance sight picture
C - use a NRA standard 100 yard rifle target (repair centers are cheaper)
D - use 6 o'clock hold
https://www.midwayusa.com/product/482791/nra-official-high-power-rifle-targets-repair-center-sr-1c-100-yard-slow-and-rapid-fire-paper-pack-of-100

<iframe width="560" height="315" src="https://www.youtube.com/embed/mnZcdk1oEVc" frameborder="0" allowfullscreen></iframe>

fnogger
July 27, 2017, 07:29
So, in a nutshell...
1 - have a good trigger
2 - learn the iron sights
3 - use known good magazines
4 - find best bullet for twist rate
5 - shoot, clean, repeat

I would add:
A - use a good solid rest and rear bag when ammo testing
B - blacken the sights (carbide or aerosol) to enhance sight picture
C - use a NRA standard 100 yard rifle target (repair centers are cheaper)
D - use 6 o'clock hold
https://www.midwayusa.com/product/482791/nra-official-high-power-rifle-targets-repair-center-sr-1c-100-yard-slow-and-rapid-fire-paper-pack-of-100

<iframe width="560" height="315" src="https://www.youtube.com/embed/mnZcdk1oEVc" frameborder="0" allowfullscreen></iframe>


Awesome. Except there are no irons on this rifle :)

nopec
July 27, 2017, 07:44
You don't mention the brand of scope or rings. Low quality optics and mounts cost a lot of spent ammo. Otherwise I agree with the break in comments.

fnogger
July 27, 2017, 07:59
You don't mention the brand of scope or rings. Low quality optics and mounts cost a lot of spent ammo. Otherwise I agree with the break in comments.

Scope is known good off my target 10/22 build. Simmons WTC 6.5-20x50 w/ AO. BIIIG scope. But known good.

Mount/rings are Burris PEPR one piece unit.

Invictus77
July 27, 2017, 08:24
I was always a fan of Simmons at the price point until an experience a couple of years ago which is somewhat similar to what you are having now. I have had several Simmons on hunting rifles as have several friends. Properly mounted and sighted in, they have always held a good zero.

My negative experience was pulling a Simmons off of one of my ARs where it have been solid as a rock for hundreds if not thousands of rounds. I was shuffling rifles & scopes around for various reasons and moved that rock solid Simmons to another rifle. After moving it and trying to re-sight it, it would not move the POA consistently during adjustment and would not hold a repeatable POI more than a couple of shots before drifting.

When new and adjusted then left alone, it remained solid. After being in moderate use however for a couple of years, I don't know if the springs get weak, springs get brittle, maybe dirt or oil get inside somehow, or what might be the cause, but it would not consistently readjust/hold zero on the new rifle after being "set" for a long time on the original rifle.

This was my only time to see this happen and may be a "one off", but it certainly sounds similar to what you are experiencing so???

YMMV

TenTea
July 27, 2017, 08:30
Awesome. Except there are no irons on this rifle :)

OK...whoops brayne freeze! :cry:

I hereby change my advice to: aim small ~ miss small

If that doesn't work, chalk it up to *operator headspace error*... :cool:

yovinny
July 27, 2017, 08:35
Fwiw,,,they usually lube the adjustments with a dab of grease when built.
That grease hardens up after awhile and can cause all kinds of issues.
Its good SOP to run the adjustments stop to stop a few times right off the line and them center mechanically befor sighting in the first time.
This stop to stop adjustment is also good practice after sitting for awhile.
Id try it before anything else...
Just my .02

Cheers, yv

Edit,,,a standard optical bore sighter makes finding a scope issue much easier also...as in you can clamp rifle in a vise and actually watch what adjustments are doing and also see any movement from tapping on scope, mount, stc...

bfoosh006
July 27, 2017, 09:45
No offense.. but your ammo choices are meant for "blasting" ... rarely will any of those shoot nice small groups.

If your rifle doesn't shoot this specific ammo well., at 100yds.. then either you need practice ( again no offense ) , or the rifle needs some QC.
That specific ammo has shot tiny groups out of every AR I have seen try it.
Don't fret about the twist rate... all mine are 1n7 and love that round.

http://www.ammunitiontogo.com/product_info.php/pName/500rds-223-federal-american-eagle-ar223-50gr-polymer-tipped-varmint-ammo

PSA makes perfectly good AR's ... but I have seen numerous ones that needed a little customer Quality control.... one's barrel nut was hand tight, another ones gas tube was being forced into the top of the receiver hole by the barrel nut, flash hiders hand tight... etc

So double check everything... don't assume it was completely assembly with QC in mind.

I have a ton of different ammo suggestions as well.
You can find all sorts of inexpensive, quite accurate ammo.

MEN 56gr FMJ, GECO 55gr FMJ ( .223 or 5.56 ) ...etc ....

hueyville
July 27, 2017, 10:47
So, in a nutshell...
1 - have a good trigger
2 - learn the iron sights
3 - use known good magazines
4 - find best bullet for twist rate
5 - shoot, clean, repeat

I would add:
A - use a good solid rest and rear bag when ammo testing
B - blacken the sights (carbide or aerosol) to enhance sight picture
C - use a NRA standard 100 yard rifle target (repair centers are cheaper)
D - use 6 o'clock hold.


Comment on Segway. I keep cans of Birchwood Casey Sight Black sitting around my indoor range and m in my handgun range bag. Front of my regular shooters have to hose them off on occasion as get a 1/2" coating of the stuff. Amazing how much better a nice flat back set of sights interact with the eye.


(Trim)
My negative experience was pulling a Simmons off of one of my ARs where it have been solid as a rock for hundreds if not thousands of rounds. I was shuffling rifles & scopes around for various reasons and moved that rock solid Simmons to another rifle. After moving it and trying to re-sight it, it would not move the POA consistently during adjustment and would not hold a repeatable POI more than a couple of shots before drifting.

When new and adjusted then left alone, it remained solid. After being in moderate use however for a couple of years, I don't know if the springs get weak, springs get brittle, maybe dirt or oil get inside somehow, or what might be the cause, but it would not consistently readjust/hold zero on the new rifle after being "set" for a long time on the original rifle.

This was my only time to see this happen and may be a "one off", but it certainly sounds similar to what you are experiencing so???
YMMV

This is not an unheard of issue. Springs get weak and a scope starts walking point of aim. Heard of cheap scopes doing out of box and proven scopes doing after years of use. I can almost feel the idea that this scope may have settled into a set adjustment and used on a rimfire handled it fine. Also recoil of a rimfire and centerfire act differently on a scope. Have seen a lot of scopes sold for large bore hunting rfiles that paperwork said specifically not for use on air rifle or rimfire. Found a deal on some Leupold rimfire scopes a few months back and purchased three so could pull nice Loopy 4-12x and 6-18x scopes off rimfire rifles and move to AR builds. Finally had to try and eventually embrace the Vortex brand to keep up with my rate of builds. Also use U.S. made Burris scopes and still put Loopy's on my premium rifles. I only own one Simmons scope and it's because it's an odd nickle plated color that matches a brushed stainless rifle no other scope did. It's a fixed 4x and used a lot on a rimfire use for pest control.

Try some different ammo (Tubbs 69 grain DTAC is my favorite factory ammo for 1:7, 1:8 and 1:9 barrels as shoots well in all of these twist rates) Some 77 grain Black Hills will be a teller, if doesn't shoot well have an issue or bad barrel. I feel a 20" 1:7 barrel should shoot good. Swap on another scope for a day if want to eliminate that. Can push out pin that holds gas tube out, remove gas tube and check barrel nut tension but if go the far I am pulling barrel, squaring receiver and reassembling meticulously. I believe you can fix without getting too involved. Double check scope is snug in rings, lighten trigger pull, shoot variety of ammo, push a lot of patches down bore till starts to shoot. It could already be copper fouled badly. A new rough barrel will collect copper like rolling a magnet through a machine shop. Till get it broken in, keep it clean, once shoots well then don't clean till it shows a need. Your trying, that's most of the battle.

hagar
July 27, 2017, 12:09
If you reload, try 60 grain V Max or Sierra with 25 grains of RL15/Varget, very few heavier bullets will beat this combination at under 300 yards.

The 50 grain Federal is 1/2 moa ammo in my Remington VS 1 in 12 twist, but the 1 in 7 may be a little much for them.

MistWolf
July 30, 2017, 14:38
To optimize the mechanical precision of an AR-
-Quality barrel
-Matched bolt
-Quality ammo
-Free float handguard
-Un-threaded muzzle or using 5/8x24 threads instead of 1/2x28

Some claim that torquing the barrel nut to 40-45 ft-lbs helps. Over torquing the muzzle device can also have a negative impact on mechanical precision.

To improve practical precision-
-Quality sights
-Consistent and predictable trigger pull
-Correct LOP & eye relief
-Good shooting technique

hueyville
July 30, 2017, 17:59
I HATE 1/2"28 MUZZLE THREADS!!! Not enough meat left on end of bore for proper crown and not have belling issues. On my nice barrels pay the extra for 5/8"24 or more if tube is fat enough. My true varmint tubes have no muzzle device, they are 0.750" to 0.850" at muzzle with 11 match crown. Do not want any dimensional change or aberrations as bullet exits crown. Just one more bit of additional tolerance stacking. If square front of receiver and use a good bolt then it will be matched, basically want bolt and barrel to be as near to perfectly lined up as possible so bolt face is perfectly perpendicular to chamber so round seats square to chamber and throat. Every thousandth of alignment issue removed during the build process pays at the target.

Have some under $400 rifles with under $100 barrels and lots of junk box parts that shoot well under MOA but took a lot of meticulous hand fitting along with trial and error. Can swap muzzle device and group might open with light bullets but close with heavies based on how it affected barrel harmonics. Can change ft/lbs of torque on same muzzle device and chang group size. Have sat at a bench with four weights of buffers, four muzzle devices and four loads mixing and matching and making tweaks till discovered H3 buffer with one less turn on adjustible gas, muzzle device "C" torqued o "x" ft/lbs with load number 2 shoots half MOA less than when started with H2 buffer, muzzle device "A" and load number 1. It can drive a man crazy if he let's it.

Can remember working up 20 different load combinations for a custom turn bolt that rifle smith tested with five different brakes before he had barrel harmonics tuned to his liking. Watched him change the angle of four holes two degrees and test again. If willing to really lay into being loony every rifle can be made better and a better load found though I now have a group of standard loads in each cartridge and whichever one does best, stopped chasing tenths of an inch. Of course make five changes that each get you a few hundredths to a tenth and suddenly a rifle is shooting 1/3 MOA less than where began. That 1/3 MOA when dialing up a crow at 325 yards with a 5 mph quartering wind is a solid inch or more of variability of where round will land removed from your firing solution. I need that inch so days.