Could barrel nut type/free float handguard affect accuracy

wmvdg123

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Minuteman
Apr 30, 2017
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Albany, oregon
Hi guys,
I built an ar-15 with a thin profile WOA barrel but it only shoots 1.5 moa groups with berger/hornady sierra bullets despite a thorough work up. I bought a bcg from white oak arma for the barrel. I lapped the upper receiver, free floated the gas tube, locktited the upper reciever/barrel. I bought q varmit barrel from WOA but it shoots only slightly better.
Could this be due to my handguard and barrel nut?

Any ideas to improve my build?
Thanks!
Wayne
 
I also have a WOA varmint barrel, which is about 1.25 MOA with my best 69 matchking load. It just will not shoot heavies. I had done quite a bit of research, and the conventional wisdom was that the chamber they spec for these was meant to shoot 50 to 55 grain bullets. It makes sense if you would take this out prairie dog hunting, i guess.

I have not loaded up any lighter weight rounds to test this theory, but it seems plausible.

Hopefully someone can chime in with a more definitive answer. It sucks because my AR looks awesome with its 26" bull barrel and 18" handguard. (yes, MI did a short run of these a few years ago)
 
Hi guys,
I built an ar-15 with a thin profile WOA barrel but it only shoots 1.5 moa groups with berger/hornady sierra bullets despite a thorough work up. I bought a bcg from white oak arma for the barrel. I lapped the upper receiver, free floated the gas tube, locktited the upper reciever/barrel. I bought q varmit barrel from WOA but it shoots only slightly better.
Could this be due to my handguard and barrel nut?

Any ideas to improve my build?
Thanks!
Wayne


Maybe try a real handguard set up. $49.95 Chandler Hardwoods might not get you the best fit for barrel/reciever
 
I have one of these in 15” black mlok I would sell you for $220

This is pretty good advice. The Aero M4E1/M5E1 enhanced platforms take a lot of variables out of play by making the handguard part of the upper receiver. They're also stupidly easy to build since there's no gas port hole and rail alignment issues. You pay a bit extra (not much, really) and you're a bit limited on handguard choices, but it's my first choice these days.

However, all of that said, I'd like to know a bit more about the ammo the OP is using.
 
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I had an AR that I changed out every part of the upper barrel, bcg, bolt, gas system, hand guard. Finally changed the receiver and groups shrunk. Still the barrel only shoots one load well, but at least now I have something under a 1”. For the new receiver I used a very thick billet receiver. I changed after a friend said the same thing had happened to him. Some how the receiver was slightly twisted or on some way too far out of spec and nothing seemed to work. He used a mega receiver but I couldn’t get one of those. Mine is now a tacticool side charge, I got it from Brownells. But it was the most solid upper I could find at the time.
 
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Yea, I have the DPMS lo pro receiver, its thicker than normal receivers. I know its a crappy hand guard. Just trying to figure out why it won't shoot. I'm going to get a Young BCM, if this doesn't help then I'll try a better handguard...
 
Yea, I have the DPMS lo pro receiver, its thicker than normal receivers. I know its a crappy hand guard. Just trying to figure out why it won't shoot. I'm going to get a Young BCM, if this doesn't help then I'll try a better handguard...

1.5 MOA isn’t bad for an AR but prob can shrink it down some. 5.56 NATO chamber? Whats the barrel twist?

Did you use a reaction rod to secure the barrel when installing and torquing the barrel nut?

As far as your load, what bullet, primer and brass you using?
what is the cartridge-chamber headspace gap (.001, .002, more case expansion)?

SD/ES?

I Have a WOA barrel and headspaced bolt in my 6.8 and it shoots .75-1.00 with hand loads (110g accubonds) and holds that to 400 (haven’t taken further yet). Handguard is a larue 9.0 quad rail.
 
and this will be relished, I am sure here but...... build something with a manual bolt when seeking precision. but, this is just my opinion.
1.5 moa isnt great but isnt bad either, out of an AR
 
I have noticed that group sizes will change when I adjust the adjustable gas block on my guns.

How many rounds down the barrel? Some barrels need to be fouled or some rounds to settle down. I have a Ballistic Advantage barrel that wasn’t impressive in the beginning but is improving with every range trip.

Try swapping out the muzzle device. Some seem to cause problems.

Shoot across a bag. Bipods can sometimes cause accuracy issues.
 
I'm going to get a Young BCM

This will change nothing...waste of money...

and this will be relished, I am sure here but...... build something with a manual bolt when seeking precision. but, this is just my opinion.
1.5 moa isnt great but isnt bad either, out of an AR

I have a precision AR that shoots less than 1moa with my hand load. I have competed in 223 only PRS type matches with it and placed higher than a lot of guys with bolt guns.

barrel nut torque ?

Possibly. I have built plenty of precision AR's and as long as you are at least at the min torque I have never noticed barrel nut torque to really be an issue. Depending on the handguard you may even have to exceed the max torque from the TDP in order to line up gas tube notches. This is "generally" frowned upon, but again, ive never seen it be an issue and I have exceeded torque values by 20-30 ft. lbs on a few installs(Noveske NSR to name one...wasnt happy about that one for the money spent, but it was what it was).
 
To the OP:

Have you ever shot your rounds across a chrono to see what they are doing? You say "your best handloads"... I only load develop across the chrono anymore which takes the indian out of the equation so to speak. Find your load with the lowest ES/ED and also safe pressure levels, and run it.
 
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I never bond the barrel to the upper on the initial build, I test the barrel fist if it shoots then I will disassemble and bond the barrel.

If the barrel is crap bonding it wont make it a whole lot better.
 
I have found "squaring up" the front of the upper receiver does wonders for improving the accuracy of an AR-15. I use a lapping tool with compound to make sure the receiver is straight where the barrel extension mates up. I also use Locktite bearing race "glue" to remove any clearance issues when inserting the barrel into the receiver. I have made 1.5" groups go to .75" groups by doing this. I always us top quality parts also. I use the BCM KMR free float handguards on all my builds, they seem to work better.
I found over time that this seemed to be the most "bang for the buck" when building an AR. A lot of little things add up to increase accuracy. Also use a reaction rod when torque is applied to the barrel nut.
 
Wayne, what about the rest of the build?

What trigger are you using? What are your hand loading techniques and components? Do you shoot off sand bags fore-and-aft? What are your powder charges? Have you tried flat-base bullets? Are you loading with ogive contact, free-jump, or forced into the lands? Iron sights or scope? Have you checked your optics and mount-to-upper? Parallax?
 
Wow so many responses, thank you all.
Barrel torqued to 60 ft lbs with a real avid armors kit, reciever squared with brownells lapping tool, loctited with green 620 loctite.
Trigger is a timney.
Using sandbags.
Scope is a vortex 1-8x eagle, I know its not the best.
Lower is just anderson, upper dpms thick wall.
I had a savage 338 Lapua that would shoot 0.5 moa consistently with my handloads. Of course someone else probably could shoot much better than me, but I'm not a terrible shooter.
The reason I'm trying the young BCG is because on another forum another person have the same barrel and it wouldn't shoot until they got a young bcg.
I'm going to try the new BCG, and then I'm going to take off the handguard and see if that has any effect on accuracy. The barrel probably hasn't been shot in I only have shot about 70 rounds out of it, I've spoken with some people that can say it can take two or three hundred rounds for a barrel to really settle down.
if anybody else has ideas they would be great, also I'll try to post and then a next week or two once I take the next few steps.
Thank!
 
Something I have started doing, and it seems to help, is squirting hot glue into the lower at the rear take down pin. Squeeze the upper and lower together and push the pin in. Cures most, of not all, of the receiver slop. Definitely makes the gun feel a lot better.

7F0C3070-60D9-40B7-854B-DD0F23A1763B.jpeg
 
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This is the biggest problem I have had. Check handguard for marks from gb. If you shoot suppressed depending on barrel length profile and gas system it makes it a lot worse. 20” .750 barrel with silencer you need like 3/16” clearance atleast. I won’t buy low profile handguards now