AR 10, how to accurize it?

Status
Not open for further replies.
G

gun'sRgood

Member
Joined
Feb 16, 2021
Messages
908
I have an AR10 by Black Rain. It's been apart a few times and has a new drop in trigger. That's because the original trigger was the best example of what a trigger should never be. Dragging a brick down a gravel road until the brick breaks is a more than fair description. I shot it at nothing just wanting to see if it it fired. When a buddy had issues with his AR10, we swapped parts and then put the Black Rain back together. The only oddity, or at least part I'd never seen was their barrel nut. It's a two piece thing that has an inner threaded portion and a threaded part that goes over the top of this. Sorry about the crappy description. Also, the muzzle brake is what is/was called a "pinecone". Or a really sharp ended oddity that I never understood. I shot this recently without any terminal muzzle device and was getting a nice 10"-12" group like target at 100yds. I'm getting back another AR10 and the tech there was talking about aligning the feed ramp. That, and so much more, I don't get since these seem to be fixed alignments? Open to any ideas.
 
Where to start.

Are you using good quality ammo or the cheapest range ammo that is available? Also try different bullet weights.

Since you stated that you get 10"-12" groups at 100 yard even without a muzzle device, I would check your barrel crown.

Are you using a free float handguard?

Standard A2 type handguards can put pressure on the barrel and cause accuracy issues if the rifle is not assembled 100% correct or something is out of spec.

One of the best things to do is to true up the front of the receiver so the barrel extension sits flush all the way around.

There are other things to look at but what I listed is a good starting point.
 
gun'sRgood said:
I shot this recently without any terminal muzzle device and was getting a nice 10"-12" group like target at 100yds.
Click to expand...
Can you describe how you're shooting, and what ammo you're using?
gun'sRgood said:
I'm getting back another AR10 and the tech there was talking about aligning the feed ramp.
Click to expand...
Matching the receiver / barrel extension feed ramps will not affect accuracy one whit; it's intended to improve feeding (altho I've never found the need for it myself).
 
12Bravo20 said:
Where to start.

Are you using good quality ammo or the cheapest range ammo that is available? Also try different bullet weights.

Since you stated that you get 10"-12" groups at 100 yard even without a muzzle device, I would check your barrel crown.

Are you using a free float handguard?

Standard A2 type handguards can put pressure on the barrel and cause accuracy issues if the rifle is not assembled 100% correct or something is out of spec.

One of the best things to do is to true up the front of the receiver so the barrel extension sits flush all the way around.

There are other things to look at but what I listed is a good starting point.
Click to expand...
I'll take a pic of the barrel nut. I'm thinking if I'm too stupid to know how to install it, I'll change it. Or gladly accept help here. Free float hand guard. White tail Hornady
 
rbernie said:
Can you describe how you're shooting, and what ammo you're using?
Matching the receiver / barrel extension feed ramps will not affect accuracy one whit; it's intended to improve feeding (altho I've never found the need for it myself).
Click to expand...
I was in a sled. I had planed on zeroing the scope. Nice sled. White tail Hornady ammo
 
1KPerDay said:
Dumb question maybe but are you capable of producing good groups at 100yards with a known-good rifle?
Click to expand...
Naw. I get it. I also shoot 1k with my 6.5CM and can hit X's 6 out of 10. This gun is about a 0.25 MOA. But you make sense. The shooter first. How many times I've heard it's the arrow not the Indian?
 
Last edited:
ClaymoreAKM said:
Start with ammo. Magtech shoots good out of my AR-10. Gonna try Israeli and Philipino stuff next.

After that trigger.
Click to expand...
This stuff should do fine. In my Wife's .308, Winchester with a muzzle brake that I made for her shoot a 1 MOA with the same stuff.
 
12Bravo20 said:
Where to start.

Are you using good quality ammo or the cheapest range ammo that is available? Also try different bullet weights.

Since you stated that you get 10"-12" groups at 100 yard even without a muzzle device, I would check your barrel crown.

Are you using a free float handguard?

Standard A2 type handguards can put pressure on the barrel and cause accuracy issues if the rifle is not assembled 100% correct or something is out of spec.

One of the best things to do is to true up the front of the receiver so the barrel extension sits flush all the way around.

There are other things to look at but what I listed is a good starting point.
Click to expand...
I was just thinking about the crown. When they put their - super weird - pinapple thing on, they seemed to just cram it on and left the barrel with a nasty little rise on the outer edge of the barrel. When I had the barrel off, I lathed that portion. So, first the crown, then the threads, then a void , then the shoulder of the barrel. That shoulder is what I lathed. this minimally increased the void. The idea of this is so when you put something on the threaded end, the threads do not continue to the shoulder of the barrel. Which may allow the "device" to cant. The squared off shoulder forces or allows the "device" to maintain alignment. BUT! I don't recall looking at the crown. I will. Is an 11 degree still the choice?
 
gun'sRgood said:
When I had the barrel off, I lathed that portion. So, first the crown, then the threads, then a void , then the shoulder of the barrel.
Click to expand...

Did you have everything setup perfectly and indicated in?

I hope that you indicated the barrel using the bore and NOT the outside of the barrel.
 
12Bravo20 said:
Did you have everything setup perfectly and indicated in?

I hope that you indicated the barrel using the bore and NOT the outside of the barrel.
Click to expand...
Yeah, gotcha. I don't have a pin set but making one for the project was simple enough. It was more or less just removing some burrs. Really careless of Black Rain to just mash it on.
 
12Bravo20 said:
Where to start.

Are you using good quality ammo or the cheapest range ammo that is available? Also try different bullet weights.

Since you stated that you get 10"-12" groups at 100 yard even without a muzzle device, I would check your barrel crown.

Are you using a free float handguard?

Standard A2 type handguards can put pressure on the barrel and cause accuracy issues if the rifle is not assembled 100% correct or something is out of spec.

One of the best things to do is to true up the front of the receiver so the barrel extension sits flush all the way around.

There are other things to look at but what I listed is a good starting point.
Click to expand...
If you would, I would greatly appreciate anything else to look at to accurize an AR platform. Thanks.
 
gun'sRgood said:
It was more or less just removing some burrs. Really careless of Black Rain to just mash it on.
Click to expand...
Sounds like they were trying to time the brake and either didn’t cut the shoulder back far enough to use shims and/or botched the size of the brake and just decided to torque it on until it lined up. Definitely not the right way to do it.

Pictures and a timeline of what was changed (with accuracy at each point) might be helpful. If we know it was shooting 4” groups with a gritty trigger, and then 10-12” groups after you pulled the barrel, it’s a good bet that the issues were caused when the barrel was pulled.

To be honest if you pulled the barrel, stripped it, and put it on a lathe, you introduced a whole bunch of variables for potential errors beyond the standard question of “how do I improve accuracy”. At this point, I’d just say that the barrel was screwed and start over. Any errors are probably at the muzzle, so I’d put it in the lathe, ensure it was correctly trued, and then part off the barrel behind all the previous work and start from scratch with a new crown and threads.

Be very careful and exact in your measurements, and use a good thread spec when you’re cutting your threads. Things like the specific size of the threads, shoulder, and undercut should be in there. Here’s one example from TBAC, and there are some other good ones out there as well.
https://thunderbeastarms.com/tech/thread-specifications

Good tools are invaluable as well. I’d recommend getting good indicating rods, and making sure your indicators and spider are up to the task.

Outside of that, I’d just get another barrel and chalk it up to a learning experience. After that, I’d reassemble everything making sure I was doing it correctly. I’d probably recommend swapping the handguard to a good/known brand if you think the current one might be causing issues, but I wouldn’t expect a handguard alone to cause a 10-12” group.



Other things to look for if you’re able to use a lathe to accuratize an AR might be cleaning up the threads on the receiver and squaring the face, and essentially all the other stuff you’d do to blueprint a bolt action. If you really want to go down that rabbit hole, you can also look at the chamber and the barrel threads/barrel extension line up. Just be aware that headspace is set by the barrel extension, and any changes there will likely affect barrel timing which means your gas port may not be vertical anymore. But if you’re going that far, you might as well start with a barrel blank.
 
Telekinesis said:
Sounds like they were trying to time the brake and either didn’t cut the shoulder back far enough to use shims and/or botched the size of the brake and just decided to torque it on until it lined up. Definitely not the right way to do it.

Pictures and a timeline of what was changed (with accuracy at each point) might be helpful. If we know it was shooting 4” groups with a gritty trigger, and then 10-12” groups after you pulled the barrel, it’s a good bet that the issues were caused when the barrel was pulled.

To be honest if you pulled the barrel, stripped it, and put it on a lathe, you introduced a whole bunch of variables for potential errors beyond the standard question of “how do I improve accuracy”. At this point, I’d just say that the barrel was screwed and start over. Any errors are probably at the muzzle, so I’d put it in the lathe, ensure it was correctly trued, and then part off the barrel behind all the previous work and start from scratch with a new crown and threads.

Be very careful and exact in your measurements, and use a good thread spec when you’re cutting your threads. Things like the specific size of the threads, shoulder, and undercut should be in there. Here’s one example from TBAC, and there are some other good ones out there as well.
https://thunderbeastarms.com/tech/thread-specifications

Good tools are invaluable as well. I’d recommend getting good indicating rods, and making sure your indicators and spider are up to the task.

Outside of that, I’d just get another barrel and chalk it up to a learning experience. After that, I’d reassemble everything making sure I was doing it correctly. I’d probably recommend swapping the handguard to a good/known brand if you think the current one might be causing issues, but I wouldn’t expect a handguard alone to cause a 10-12” group.



Other things to look for if you’re able to use a lathe to accuratize an AR might be cleaning up the threads on the receiver and squaring the face, and essentially all the other stuff you’d do to blueprint a bolt action. If you really want to go down that rabbit hole, you can also look at the chamber and the barrel threads/barrel extension line up. Just be aware that headspace is set by the barrel extension, and any changes there will likely affect barrel timing which means your gas port may not be vertical anymore. But if you’re going that far, you might as well start with a barrel blank.
Click to expand...
Excellent!. I'll put up a few pics. I think I'm far enough along to be ignorant of what I'm ignorant about. Or know enough to know, I should know more before taking things apart and playing with them. This thing is a .308 and unless you see otherwise, I think I'd rather have something is a 6 something er other. That 6.8 seems like a good route to go. But most of all, thanks!
 
I’ve yet to hear a whisper of bad about Black Rain, and by admission, you’ve taken it apart for reasons other than performance (to swap parts with a friend).

Things we don’t know:
1. How did it shoot day 1-the day you disassembled it?
2. How did you disassemble? With correct tools or by any means?
3. How did you reassemble? Torque specs (and do you know what they are for an AR-10?
4. Why would you run your barrel on a home lathe for a timing issue? They make crush washers and shims to time align. That’s begging for damage, a voiding of warranty, and inducing stress to a finished barrel.

A whole lot makes zero sense here to me, especially how a rifle you previously used and appeared to have no problem with, ended up performing like a shotgun. Bad trigger or not, an accurate rifle is still accurate, even if more difficult to shoot well. You may well be out a barrel at this point, hopefully no more than that.

Your forearm is free floated, won’t affect accuracy. Your feed ramp alignment should not change accuracy between day 1 and now, at worst they would hinder smooth feeding and potentially damage the bullet- something you could check by chambering a few rounds then carefully clearing the weapon.
 
I’ve built literally hundreds of AR-15’s and AR-10/LRAR’s over the last 22yrs, and honestly, if you’re talking about 10-12” with any load and I were a shooter which could hold 1MOA at 1,000 with another rifle (although shooting sub-MOA with an AR is much harder than with a stickshift), I personally wouldn’t waste time with that barrel any longer. 10” at 100yrds is a dog which won’t hunt, and frankly, it’s too easy to waste time, money, and energy on a barrel like that and never get anywhere truly acceptable.

MOA to Sub-MOA accuracy with AR’s - in hands of folks used to shooting them - isn’t terribly complicated. Proper quality barrel, shimmed or bedded extension, free float tube, proper trigger, and good support and properly tuned feeding to avoid damage to the ammo on the way from mag to chamber, with ammo the rifle likes. Shilen, Krieger, Proof, Bartlein/Craddock. Guys get all axle wrapped about headspace matched bolts, but honestly, I’ve not found any substantial improvement in using matched versus non-matched bolts. I lap my lugs for consistent and uniform contact and load my ammo... not terribly complicated. Maybe I’m just ridiculously lucky, but frankly, I don’t buy that.
 
sarduy said:
You don’t, you buy a bolt action instead. The AR10 was never meant to be super accurate, it’s a battle rifle in 7.62 Nato. There are AR platforms purposely build for accuracy like the SR25 and the M110, but even that has it’s limitations.
Click to expand...
Years ago my Wife bought this gun for me. It sold for some $2,600. To toss it is not an option. To give up is not an option. To learn something and go forward with new knowledge is highly desirable. Perhaps it's sort of a baby and the the bath water. I have several AR15's that all shot a 1MOA. Heck I've got a 10.5 .300 and 5.56 that shoot close to a 1 MOA. With all the new tooling out there, accuracy of these formats becomes greater every day. When I bought my first 6.5CM I was told that it was dumb and the .308 would always remain the top dog. But I remember what you mean. Thanks
 
Here is the best deal you'll find, they have 20" also ready to ship for $10 More ! All you need is the appropriate free float foreend nut , no hokey ones please ! Torque with proper grease to specs (DPMS) . If you check the contact pattern of the old barrel markings on reciever face you should be able to tell if the receiver needs machining or at least use barrel with compound to lap it in and clean well .

https://www.joeboboutfitters.com/Fa...LUTED-308-WIN-M-p/fax-10b810r18fhq-5r-np3.htm

I went with Criterion 18" Hybrid barrel with M118 chamber and rifle length gas tube.With my Standard .308 test load for all my .308s of Federal Gold Medal Match 168 grain Ammo it produces JUST over 1" with a Leupold 4-14 x44 scope .

IMG_20180402_151047104_HDR.jpg
 
Last edited:
Gordon said:
Here is the best deal you'll find, they have 20" also ready to ship for $10 More ! All you need is the appropriate free float foreend nut , no hokey ones please ! Torque with proper grease to specs (DPMS) . If you check the contact pattern of the old barrel markings on reciever face you should be able to tell if the receiver needs machining or at least use barrel with compound to lap it in and clean well .

https://www.joeboboutfitters.com/Fa...LUTED-308-WIN-M-p/fax-10b810r18fhq-5r-np3.htm

I went with Criterion 18" Hybrid barrel with M118 chamber and rifle length gas tube.With my Standard .308 test load for all my .308s of Federal Gold Medal Match 168 grain Ammo it produces JUST over 1" with a Leupold 4-14 x44 scope .

View attachment 1030901
Click to expand...
Nice! Very nice!. A while back I was doing a project and using BSF. They are a carbon fiber barrel company. Smaller than the other two but have captured a few military contracts. Anyway, I became friends with one of the sales guys and now have a onetime deal to get a barrel of my choice at cost. That 6.8 may become a reality. It's all the .308 stuff you accumulate over time. Brass, lots of bullets to load, the dies, etc.
 
6.8 requires a new bolt head and magazines , for an AR15 yeah, for a AR10 nay ! .308 is common , 6.8 not so much !
You haven't learned your lesson about the "trick" stuff yet it sounds like concerning barrel nut weirdness and going with a carbon fiber wrapped barrel on your AR10 problem ? Go with what is known by many of us here who got great results with "conventional" high quality (known) barrels and barrel nuts ect. versus the latest and greatest sales pitch crapshoot ?
Your choice, just avoiding another unhappy experience is something I learned about 30 years back .
 
Status
Not open for further replies.

Similar threads

C
  • Locked
AR 308 build
Replies
8
Views
2K
illinoisburt
illinoisburt
GravelRider
  • Locked
How far out can a stock AR10 in 308 reasonably be expected to shoot accurately?
2 3
Replies
51
Views
2K
C-grunt
C-grunt
C
  • Locked
questions about bullpup 10/22
Replies
12
Views
5K
Bigfoot
B
G
  • Locked
A quick review of my New PSA-10
Replies
2
Views
638
grubbylabs
G
W
  • Locked
Going rate?: Armalite AR-10 A4 Carbine
Replies
6
Views
1K
W L Johnson
W
Back
Top