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alamo5000
19 September 2016, 18:58
I am doing my usual window shopping for all kinds of things preparing to make several strategic purchases over the coming weeks or months. One of those purchases will probably be the start to an AR10 build. It might take me a while to have em all built up but I am slowly but surely going to be making some purchases especially now that my job is hopefully going to stabilize in the next few weeks.

Is it me or does it seem like AR10 components are harder to come by these days? I might just be going crazy but it seems like some of the higher end manufacturers are going to a 'few times a year' run system. IE make a run, sell it out, make a run, sell it out and not sitting on inventory.

When I built my first AR platformed gun I was specifically keen to barrel selection and believe it or not bolt selection. This time around and after a couple other builds I am a little more aware of what I'm after but I will still ask for recommendations.

1)Does anyone know of a company that makes nitride AR10 bolt carrier groups? If say I could find a comparable BCG to something like the Fathom black nitride bolt I would be good to go. I am looking for something of that caliber of worthiness/reputation. I don't need a $400 BCG but I also don't want a fugly junky one either. Some of them I see I have either ignorantly never heard of them or I don't like how they look (IE ugly logos or whatever).

2)Can anyone recommend a good precision AR10 barrel? I am thinking something along the lines of the Rainier Select line (which I am extremely pleased with) but to my knowledge they don't come in .30 caliber. To me that's a known quantity so I am highly confident in it. My two main concerns are accuracy and a reasonable barrel life. I prefer it to come in black. [:D] I will probably get down to twist rates and type of rifling and all that too (maybe) but we will see. Basically I want it to relatively accurately shoot heavier bullets at longer ranges (1000+).

FYI the gun will be DMPS styled.

Former11B
19 September 2016, 19:34
You absolutely can't go wrong with a Rainier Match/Ultra Match AR10 barrel. Since you're looking at 1000yds, I'd go with a 20" model. I cut mine to 16" to make a more balanced package when suppressed, and more maneuverable in general, but I feel like my absolute max is 800yds....600 is more realistic for repeatable and confident hits (for me, anyway).

Here is a BCG you might be interested in:
http://aeroprecisionusa.com/308-bolt-carrier-group-black-nitride.html

alamo5000
19 September 2016, 20:59
You absolutely can't go wrong with a Rainier Match/Ultra Match AR10 barrel. Since you're looking at 1000yds, I'd go with a 20" model. I cut mine to 16" to make a more balanced package when suppressed, and more maneuverable in general, but I feel like my absolute max is 800yds....600 is more realistic for repeatable and confident hits (for me, anyway).

Here is a BCG you might be interested in:
http://aeroprecisionusa.com/308-bolt-carrier-group-black-nitride.html

Thank you for the response. It's going to be a while before I start building yet so I have time... but I will for sure put them on the list though.

As with other things the exact final product is TBD. That said I've shot a 26" .308 bolt gun out to 1000 yards. I found that the round had more 'oomphf' still left in it. The limitations in our specific case was actually the scope and scope mount and of course the ammo. I think I could have hit beyond 1000 yards had it not been for us running that scope with a cheap mount on a borrowed gun with factory ammo.

I did some ballistic chart tests and I think 1000 is doable with an 18 inch barrel but again absolutely nothing is finalized yet. I am planning on a bolt gun of some sort too to maybe scratch that really long itch but that is in preliminary stages.

Realistically a .308 round will go trans sonic between 1000-1100 yards but it depends a lot on the bullet.

Bullet selection has a huge impact on what's gonna happen.

A regular 168 gr SMK has a BC of .462
A tipped 168 gr version has a BC of .535
A tipped 175 gr has a BC of .545

Berger 168's are .515
Berger 175's are .512

Among the three a tipped 168 grain SMK leaving the barrel at 2530 fps or above would be supersonic still at 1200 yards...depending on the weather of course :)

Now check out this link... look at the chart

http://rifleshooter.com/2014/12/308-winchester-7-62x51mm-nato-barrel-length-versus-velocity-28-to-16-5/

http://i1320.photobucket.com/albums/u538/Alamo_5000/Capture1_zps3lq9nouh.jpg

Based on 2500 FPS velocity I would at least in theory still be banging supersonic beyond 1100 yards and just about 1200 yards based on better bullet selection alone.

http://i1320.photobucket.com/albums/u538/Alamo_5000/Capture2_zpsdseg5ano.jpg

Even out of a 16.5" barrel using 168 tipped matchkings and the rough data from that test above...2450 muzzle velocity I would also still be supersonic at 1100 yards.

I am thinking it through all the way.... I am going to take into account shooting heavies with this one so I can reach out there. I am also going to be more particular about scope selection.

I can only ask the rifle to do so much and I am thinking 1000 is my benchmark... I know for a fact that it can be done but I think I can improve on the performance some especially when I am not using factory ammo and a borrowed rifle. 1100 or even 1200 is butter should I decide to go with a longer barrel.

alamo5000
19 September 2016, 21:06
Basically that's what happened to us...#1 we ran out of adjustment on the scope....so no questions asked I am going to have a 20 MOA base. If I can find one with more I will consider that as well. Insurance never hurts. Even with what we were doing an extra 20 MOA would have been extremely nice. We had to get down on the hash marks after we ran out of adjustment... but once we hit it... we kept on hitting. It was like clockwork. I think I hit 10 out of 10 shots at one point, but on average it was 7 or 8 out of 10 shots were hits at a grand even across several shooters.

All that stuff said though I am going need to decide if I want a 1:11 or 1:12 barrel. At this point I am leaning 1:11 for the barrel...it's unlikely that I will go over 175 grain bullets....

alamo5000
19 September 2016, 21:16
I cut mine to 16" to make a more balanced package when suppressed, and more maneuverable in general, but I feel like my absolute max is 800yds....600 is more realistic for repeatable and confident hits (for me, anyway).


Which bullets are you using? I would be curious to see if you would experiment with some of these others that I mentioned and work up a load to test... see if my theories actually work or not [BD]

gatordev
20 September 2016, 06:30
I've had such a frustrating time with my Rainier barrel that I can't recommend it. You can see the progress in my thread. The rifle is fully functional now, but it required a lot of extra expense to get running. So far, I'm still not finding it to be as precise as my SR-25, either, but it's tough to fully commit to that statement given shooter error.

As for length, I've stood next to a 16" Larue that went out to 900 with no problems (it was the limit of the range). I think I took it out to 800. I believe Larue was making 11.25 barrels at the time and the rifle was using FGMM 175s. I'm not arguing with 11B's personal experiences with his rifle, but it's possible get reliable shots with a smaller barrel, assuming it was built well enough.

Like 11B, I'm not convinced my Rainier barrel will do it, though. Hopefully in 3 weeks, I'll take it out to 850 and see how it works.

alamo5000
20 September 2016, 06:48
Gator can you post a link to your progress thread? I want to read it and maybe poke around some to try and learn from it.

gatordev
20 September 2016, 07:12
Here you go... http://www.weaponevolution.com/forum/showthread.php?9143-Failure-to-Extract-problems&highlight=

Slippers
20 September 2016, 07:21
Alamo, I think something is slightly off with your calculations. The 168 SMK usually goes transonic around 700-800 depending on velocity, and it does poorly in the transition to subsonic speeds, keyholing. You can run the 175s out past 1100-1200, and they remain stable even as they slow all the way down. Most people recommend not using the 168 past 600 yards, even. I can't remember if it was F2S from KAC on m4c, but I remember reading guidelines to not bother bringing 168 SMK based ammo to some of their long range classes.

The issue with building an "AR10" is that there are so many variations of the platform, and component selection is limited. I have a very good friend that is going through buyers remorse on his Mega Maten based build, which happens to use a Rainier Ultramatch barrel. It won't cycle reliably with any ammo, and he's gone through several bolt groups, buffer combinations, and even tried an SLR adjustable gas block. Each company blames the malfunctions on someone else, so he gets to play musical chairs trying to get support, and wastes money shipping parts back and forth.

The main reason he chose to build the rifle in the first place was to save money, but he's now spent more on his rifle than a brand new LMT MWS.

I recommend getting a complete factory rifle. I'm a bit biased, but I like LMT, or you can of course spring for a KAC SR25. If you have issues, you have someone to call, and you have a warranty.

alamo5000
20 September 2016, 07:42
Alamo, I think something is slightly off with your calculations. The 168 SMK usually goes transonic around 700-800 depending on velocity, and it does poorly in the transition to subsonic speeds, keyholing. You can run the 175s out past 1100-1200, and they remain stable even as they slow all the way down. Most people recommend not using the 168 past 600 yards, even. I can't remember if it was F2S from KAC on m4c, but I remember reading guidelines to not bother bringing 168 SMK based ammo to some of their long range classes.

The issue with building an "AR10" is that there are so many variations of the platform, and component selection is limited. I have a very good friend that is going through buyers remorse on his Mega Maten based build, which happens to use a Rainier Ultramatch barrel. It won't cycle reliably with any ammo, and he's gone through several bolt groups, buffer combinations, and even tried an SLR adjustable gas block. Each company blames the malfunctions on someone else, so he gets to play musical chairs trying to get support, and wastes money shipping parts back and forth.

The main reason he chose to build the rifle in the first place was to save money, but he's now spent more on his rifle than a brand new LMT MWS.

I recommend getting a complete factory rifle. I'm a bit biased, but I like LMT, or you can of course spring for a KAC SR25. If you have issues, you have someone to call, and you have a warranty.

I have heard about some people having issues with the AR10 platform so that is part of the reason for my hesitation. When I built my first AR I didn't know anything so that had me all twisted up. In this case I know a little bit more but I keep hearing about how they can be fincky or whatever. Truth be told I am extremely tempted to just build me a really good bolt gun (hence the other thread) and be done with it. At the ranges I intend to take it to that might be a better overall option.

I am really going back and forth between the two. Then I develop WEVO-itis which is to 'just get both!'...but I think a good bolt gun set up how I like it might be a better choice for the bigger calibers.

As for the calculations... I posted the results from Hornady's online ballistics calculator. I used the BC of a Sierra Tipped 168 grain (.535) and the velocity estimates were drawn from that test at the link above. Put the numbers in and double check for me to see if I am missing anything. I am all ears before I start forking out 100 dollar bills I want to be sure.

I know for 100% sure that I personally was hitting on the 1000 yard plate with a borrowed gun that gave a muzzle velocity of around 2600fps using Federal Gold Medal Match and that's just using the standard non tipped SMK. Even that bullet out of that gun was still just barely supersonic at 1000 yards according to the ballistics calculator.

Slippers
20 September 2016, 08:00
Tipped 168 may be fine. I have no experience with them. If you dig around online you'll see dozens of reports about the normal 168 being pretty awful past 700-800. From what I understand it was designed as a 300m bullet, in the first place.

The 175 is a different design, which is why it's stable as it goes transonic. As a reference point, genuine M118LR chronos at 2500 fps out of my 16" MWS. It'd be tough to push the 175s much faster since M118LR is pretty hot to begin with.

alamo5000
20 September 2016, 08:27
Tipped 168 may be fine. I have no experience with them. If you dig around online you'll see dozens of reports about the normal 168 being pretty awful past 700-800. From what I understand it was designed as a 300m bullet, in the first place.

The 175 is a different design, which is why it's stable as it goes transonic. As a reference point, genuine M118LR chronos at 2500 fps out of my 16" MWS. It'd be tough to push the 175s much faster since M118LR is pretty hot to begin with.

Whether or not I go with tipped 168's or tipped 175's or just plain old 175's or berger bullets or whatever...that's the arena I'm looking at. If I want to get past 1100 or 1200 yards that would require a different caliber and it would kick me up waaaay over budget in the optic department. I need to take that into account too. I would love to have it, but a $3 or $4 thousand dollar optic is out of my price range.

There are a lot of choices to be made. I am leaning heavily towards the .308 because I can get loads of brass and bullets and shoot it for relatively cheap. I can reload for .50-.60 cents a round and be golden as a goose. I am not sure about other calibers but once I hit that 1200 yard button it kicks me up in the optic area for most calibers....

I still have to decide bolt gun or AR10 platform and I keep on going back and forth between them. I am really kind of torn. Not sure what direction I will go first.

Former11B
20 September 2016, 10:45
I've had such a frustrating time with my Rainier barrel that I can't recommend it. You can see the progress in my thread. The rifle is fully functional now, but it required a lot of extra expense to get running. So far, I'm still not finding it to be as precise as my SR-25, either, but it's tough to fully commit to that statement given shooter error.

As for length, I've stood next to a 16" Larue that went out to 900 with no problems (it was the limit of the range). I think I took it out to 800. I believe Larue was making 11.25 barrels at the time and the rifle was using FGMM 175s. I'm not arguing with 11B's personal experiences with his rifle, but it's possible get reliable shots with a smaller barrel, assuming it was built well enough.

Like 11B, I'm not convinced my Rainier barrel will do it, though. Hopefully in 3 weeks, I'll take it out to 850 and see how it works.


I have 2 Rainier Match barrels right now and both are in 5.56. I no longer have an AR10 because I didn't, and still don't, shoot .308 enough to justify what I had in it. I was using a Rainier Arms 20" .308 Match barrel and adjustable gas systems on all three rifles, but the .308 by far needed it more than the others (Syrac gas block on 308 and WAR Uppers on 5.56). I was also using a rifle length buffer and A2 stock. It was shot suppressed 99.9% of the time, and I rarely shot it anyhow...basically enough to load test for it, zero the scope, and get DOPE.

Sorry to hear yours is giving you trouble; I've only ever had great experiences with Rainier barrels which is why I recommend them nonstop


Which bullets are you using? I would be curious to see if you would experiment with some of these others that I mentioned and work up a load to test... see if my theories actually work or not [BD]

My R700 is the 16" rifle I mentioned not being comfortable out past 600 yards, despite the rifle itself being able to make the shots, I just don't feel like I can personally get consistent results at 800yds. As far as the load I shoot, the 1:10 twist heavy barrel loves 168gr Nosler CC's or SMKs, and I've just started shooting 168gr TMKs. 43.gr of RE15 and BR2 with good results from 100-300yds but haven't shot them any further yet. Maybe my opinion about longer ranges with this rifle will change.

I understand that velocity wise, the rounds might be supersonic and might still have the juice at those distances to remain stable and accurate, but I'm not doubting the platform so much as myself at any rate.




I still have to decide bolt gun or AR10 platform and I keep on going back and forth between them. I am really kind of torn. Not sure what direction I will go first.

Honestly, you could start with a bolt gun (I'd recommend going with a detachable bottom metal if so...internal magazines get frustrating). You could opt for a .30-06 (very popular and marginally more expensive than .308) which'll get you some more range without crossing into .300WM territory, and it'll allow you to decide if long range rifle is something you are interested in enough to build a semi-auto. I found, after doing BOTH, that I didn't have the time for one thing to invest in shooting so many different rifles, and I also didn't have a need to shoot 1000yds. I turned my .308 bolt gun into sort of a suppressed scout rifle and I'm happy with it.

Former11B
21 September 2016, 15:53
FYI, Rainier is have a sale on their brand of match barrels (10% off code: barrel10 ) and Ultramatch (15% off code: barrel15 ) through September 25th

Sak007
21 September 2016, 17:03
FYI, Rainier is have a sale on their brand of match barrels (10% off code: barrel10 ) and Ultramatch (15% off code: barrel15 ) through September 25th

Finally a sale that coincides with a part I need , now 308 16in match or ultra match & rifle or carbine length gas?

Former11B
22 September 2016, 05:10
You'll have no issues with a 16" Rifle length system. Go with what you have the money for, but if I was building a rifle I was going to keep, I'd go with Ultramatch.