Are AR-10s problematic?

[762 ULTRAMAGA]

I'm looking to put a 6.5 Creedmoor AR-10 together.
I've heard a few guys say the Ar-10 platform is prone to issues like cracked bolts etc. I'd never heard this so I'm looking for feedback from guys with high round counts.
I'm looking at building with all WC parts, any suggestions otherwise?
Also will 147 eldms be an issue for oal?

 

[JohnDeereGuy1996]

I highly prefer buying factory rifles when I go large frame. Nothing wrong with building but there is no standardization. A good chance you’ll have zero issues if done properly.

 

[StaveyIL]

I’ve never had a problem . Built at least 10. I always use a Hp bolt. Usually Rubber City Armory (RCA). Their blems are a great deal. As well as an adjustable gas block. I prefer SLR sentry series. . Aside from that everything is standard. I think people over complicate things. As far as all wc parts. I’m not sure they even offer a HP bolt. I have used their detent adjustable gas block and they worked well. I don’t see why 147 eldm would be an issue. The 140 eldm has always been my go to for the 6.5 gas guns.

 

[FuhQ]

Every home built AR10 I've seen has had issues of some sort, some small and some large. And some were built by seasoned builders and still were super picky about running with certain types of ammo, and some would only run suppressed with certain ammo, but not unsuppressed with the same supersonic ammo. Just weird stuff.

I build all my AR's, but after seeing what I've seen with how finicky AR10's are, I'd go top-tier factory built if I were opting for large frame AR's. LWRC REPR, PWS, LMT, KAC, or something like that.

 

[762 ULTRAMAGA]

I’ve never had a problem . Built at least 10. I always use a Hp bolt. Usually Rubber City Armory (RCA). Their blems are a great deal. As well as an adjustable gas block. I prefer SLR sentry series. . Aside from that everything is standard. I think people over complicate things. As far as all wc parts. I’m not sure they even offer a HP bolt. I have used their detent adjustable gas block and they worked well. I don’t see why 147 eldm would be an issue. The 140 eldm has always been my go to for the 6.5 gas guns.

Right on
So the HP bolt is just a high pressure rated bcg?
I know WC uses some really high quality hardened steel on there's

 

[FuhQ]

My experiences are different than yours. There are a few large frame specific things to be aware of but they are no more difficult than AR15 to get to run correctly. Every thread I see where guys are having problems is when they don’t use standard weight parts are try and use fancy recoil spring assemblies.

I've built a pile of AR15's over the years, and never had a single issue... Not sure what people do wrong that makes them so unreliable, other than maybe not knowing what they're doing, and thinking they do... Or, buying sub-par parts from China, instead of high quality parts from reputable brands.

One of the AR10's that never ran right that a buddy of mine had was a DPMS, but then again...It was a DPMS, so what do you expect?

Another was a really high-quality build an experienced builder buddy of mine made, and his was the one that was picky with ammo and cycling suppressed vs. unsuppressed. It was the weirdest shit ever. If I hadn't seen it with my own eyes, I wouldn't have guessed he would have been having problems like that with supersonic ammo. Those are typically subsonic cycling issues.

When the cycling issue AR10 happened (last year), I was just on the verge of finally buying a receiver set to build one, and then after seeing that, I decided to back out of the idea again. Maybe I'll toy with it someday, but not right now.

 

[wade2big]

I've built a pile of AR15's over the years, and never had a single issue... Not sure what people do wrong that makes them so unreliable, other than maybe not knowing what they're doing, and thinking they do... Or, buying sub-par parts from China, instead of high quality parts from reputable brands.

One of the AR10's that never ran right that a buddy of mine had was a DPMS, but then again...It was a DPMS, so what do you expect?

Another was a really high-quality build an experienced builder buddy of mine made, and his was the one that was picky with ammo and cycling suppressed vs. unsuppressed. It was the weirdest shit ever. If I hadn't seen it with my own eyes, I wouldn't have guessed he would have been having problems like that with supersonic ammo. Those are typically subsonic cycling issues.

When the cycling issue AR10 happened (last year), I was just on the verge of finally buying a receiver set to build one, and then after seeing that, I decided to back out of the idea again. Maybe I'll toy with it someday, but not right now.

If it will be used suppressed and unsuppressed, an adjustable gasblock is mandatory. I would consider one mandatory on any large frame regardless. Gasport location on the barrel is more important as well. Rifle length gas on a 6.5 20”+ 6.5 creedmoor is a good example of what not to do. Carbine length receiver extensions and that short and light 2.5” 308 buffer is another example of what not to do.

You are correct though, small frames are the easy button.

 

[redneckbmxer24]

Buy a Seekins.

 

[762 ULTRAMAGA]

If it will be used suppressed and unsuppressed, an adjustable gasblock is mandatory. I would consider one mandatory on any large frame regardless. Gasport location on the barrel is more important as well. Rifle length gas on a 6.5 20”+ 6.5 creedmoor is a good example of what not to do. Carbine length receiver extensions and that short and light 2.5” 308 buffer is another example of what not to do.

You are correct though, small frames are the easy button.

I run 100% suppressed and plan on using a WC 20" barrel, planning on using their adjustable gasblock as well.
What would you recommend for gas tube length and buffer setup?

 

[BipThatInstance]

The real issue is, still after all these decades, a lack of standardization. You have the KAC-pattern, DPMS pattern, and some funky "AR308" patterns that say they're one or the other but have something fucking stupid going on randomly -- over/undersized pin holes, buffer threads, muzzle threads, etc.

Your best bet is buying a factory one honestly. KAC or LMT if you can even find one in stock (moreso for KACs), a JP or Seekins or if you want to experience something that doesn't work go buy the PSA Sabre fake m110

 

[tekmann2377]

If you don't understand troubleshooting a malfunctioning AR platform rifle... Don't build a large frame AR. They are WAY more finicky than a AR-15. Also there is no universal dimensional standard for the large frame AR, so there ends up being a lot of tolerance stacking from which various issues arise.

I put together a 6.5 CM AR in the early 2010's. They weren't really available commercially at that time, so I was stuck building it.

A few tips from someone who has put together several large frame AR's and troubleshooted them.
First, use the longest gas system possible. Rifle length at least.
Second, a good buffer system is an A-5 length carbine tube (which is longer than a standard AR buffer tube) and an H-2 or H-3 buffer.
Third, an adjustable gas system is generally a good idea, but is an additional potential failure point.
Fourth, I do recommend an HP bolt. This isn't because bolts are stronger or weaker. The HP bolts have a smaller firing pin and firing pin hole, and won't crater or pierce primers prematurely. This is especially important for a smaller caliber overbore cartridge, just like a Creedmoor.

If you can't wrap your head around this then I can recommend buying one instead. I think this would serve you better.

 

[FredHammer]

I found the reliability of home built AR10s came down to managing the gas port size. Drilling the port till they function, and most times it involves drilling the port larger, then harnessing any over gas conditions with adjustable gas block. Preferably a bleed off style like SA.

 

[wade2big]

I run 100% suppressed and plan on using a WC 20" barrel, planning on using their adjustable gasblock as well.
What would you recommend for gas tube length and buffer setup?

I’m not a pro by any means but I have put a few large frames together with no issues so take this for what it’s worth.

If this barrel from Wilson Combat has a rifle length gas, you will need the slightly longer gas tube or you will have cycling issues. They place drill their gas ports slightly further forward in thre barrel and an AR15 rifle length gas tube will be too short to properly mage with the gaskey of the BCG. You can call and verify but the WC barrel I had was this way. Fulton Armory is a good source for this length tube.

Gas Tube, Rifle, FAR-308 AR

Your Source for Service Rifles: M1 Garand, M1 Carbine, M14 / M1A & AR Types

www.fulton-armory.com

For the receiver extension use the Vltor RE-A5 receiver extension, rifle length recoil spring of your choice, and a H3 AR15 buffer. The Vltor tube extension is a bit longer to accommodate the longer “AR10” bolt carrier while still being able to use regular ar15 buffers. If Armalite has their AR10 6 position receiver extension kit you can use that and it comes with everything you need as well although I’m not sure of the buffer weight used in that kit.

If you want to use a fixed rifle stock then pick up a large frame rifle buffer tube kit. Aero sells one I believe they call it their M5 .308 rifle buffer kit (ext, spring, buffer) and there are others that offer kits as well such as armalite and Luth-AR or you can piece it out from whoever. Just make sure it is large frame stuff (AR10) and not AR15. I believe the difference isn’t the extension but the buffer and spring.

 

[308pirate]

So the HP bolt is just a high pressure rated bcg?

The HP mark is supposed to mean that the bolt was tested by using it to fire a proof load cartridge and then inspected for flaws using magnetic particle inspection.

 

[6.5SH]

The HP mark is supposed to mean that the bolt was tested by using it to fire a proof load cartridge and then inspected for flaws using magnetic particle inspection.

HP in the large frame arena usually refers to a smaller firing pin hole to reduce cratering.

 

[WindstormSCR]

I've built a pile of AR15's over the years, and never had a single issue... Not sure what people do wrong that makes them so unreliable

The margins for error on tuning the gas system for proper running are smaller, mostly.

90% of problems I've seen online and in person with large frame ARs are always gas system related, be it incorrect buffer weight, miscalculated port size, changing too many things at once, etc

personally, if I were going large frame I'd just get a SCAR and the lower for it that takes SR25 mags and call it a day since you'll be in for about the same cost as a large frame AR anyway. out of the box they're not fun to shoot (brake is obnoxious and they're snappy as hell for recoil), but put a suppressor and a few small buffer mods on there and they turn into hyper accurate pussycats.

 

[Hecouldgoalltheway]

The only issues I've ever had are related to head space. Quality Adjustable gas block and a jp silent capture spring seems to eliminate most of the cycling issues. (What's left is typically a magazine issue). The problem is that if you're patient you can usually catch a seekins or another quality manufacturer with a sale for less than you can buy the quality parts for. I'm more in the camp of buying a factory ar10 these days, knowing I'll only change the barrel or trigger, or something simple. If it meets 95% of what I'm trying to accomplish, I'm in.

 

[BipThatInstance]

SCAR

Honestly, this. Pretty easy to find SCAR20S' out there, secondary market too, and they're really accurate with match loads in my experience. It's just chonky but the mags are cheaper than fucking SR25 metal mags and you can also find them

(Says someone with way too much money into an SR25 E2 PR + accessories)

 

[WindstormSCR]

Honestly, this. Pretty easy to find SCAR20S' out there, secondary market too, and they're really accurate with match loads in my experience. It's just chonky but the mags are cheaper than fucking SR25 metal mags and you can also find them

(Says someone with way too much money into an SR25 E2 PR + accessories)

I actually detest the SCAR oem mags because they hard limit you to 2.8" load length, can't even use M118LR or clones, or most of the good 175gr stuff.

thus my advocating for a Lingle SR25 mag lower, and using the red follower SR25 P-mags (you also get 25 instead of 20 per mag), also widens the available trigger options you have

 

[BipThatInstance]

I actually detest the SCAR oem mags because they hard limit you to 2.8" load length, can't even use M118LR or clones, or most of the good 175gr stuff.

thus my advocating for a Lingle SR25 mag lower, and using the red follower SR25 P-mags (you also get 25 instead of 20 per mag), also widens the available trigger options you have

Yeah, that's a good point, they are squashed. And even with the Lingle you'd be in less than a KAC or LMT (well, maybe).

The PMags are good to go, I should probably dump my metal SR25 mags one day, haven't had an issue with Magpul 10s 20s or 25s...yet

 

[Charger442]

Doing some research and tuning is hard for most people and that's why they're scared of building an AR-10.

It really comes down to this: get a matched bolt and barrel extension. That's the only REAL difference. Most everything else is easily overcome. Armalite extension or dpms extension. Get the bolt matched to the barrel and barrel extension and it will run, then tune the gas system for your loads.

Easy to do a matched upper/lower combo and pick dpms chamber spec or armalite chamber spec. Handguards and buffers aren't difficult, the info is there.

Like someone said above, if you can't understand dimensions and how to troubleshoot an AR, then buy a factory gun.

 

[AZgeek]

I've only built one and its been flawless. Parts that matter the most:

Aero upper, lower and handguard
JP HP bolt with full mass carrier
SA gas block

 

[RTH1800]

I have only owned a few factory built LF AR's. All were high quality. Zero issues.
Never built one. From reading on this site there sure seem to be a lot of questions about LF AR issues with home builds. Enough to make me suspicious that they are not as simple as the SF AR's.

 

[cypriss32]

I’ve built a few (6.5 creed and 308) and I’ve learned a few things. Number one: Quality barrel; proof, Craddock, CLE, gap (high end builders). Adjustable gas block (superlative arms) and a JP high pressure bolt. Seems to fix all the issues I’ve seen with my rifles and friends rifles.

 

[308pirate]

HP in the large frame arena usually refers to a smaller firing pin hole to reduce cratering.

Awesome. More confusion compared to the 5.56 world.

 

[FredHammer]

I’m not a pro by any means but I have put a few large frames together with no issues so take this for what it’s worth.

If this barrel from Wilson Combat has a rifle length gas, you will need the slightly longer gas tube or you will have cycling issues. They place drill their gas ports slightly further forward in thre barrel and an AR15 rifle length gas tube will be too short to properly mage with the gaskey of the BCG. You can call and verify but the WC barrel I had was this way. Fulton Armory is a good source for this length tube.

Gas Tube, Rifle, FAR-308 AR

Your Source for Service Rifles: M1 Garand, M1 Carbine, M14 / M1A & AR Types

www.fulton-armory.com

For the receiver extension use the Vltor RE-A5 receiver extension, rifle length recoil spring of your choice, and a H3 AR15 buffer. The Vltor tube extension is a bit longer to accommodate the longer “AR10” bolt carrier while still being able to use regular ar15 buffers. If Armalite has their AR10 6 position receiver extension kit you can use that and it comes with everything you need as well although I’m not sure of the buffer weight used in that kit.

If you want to use a fixed rifle stock then pick up a large frame rifle buffer tube kit. Aero sells one I believe they call it their M5 .308 rifle buffer kit (ext, spring, buffer) and there are others that offer kits as well such as armalite and Luth-AR or you can piece it out from whoever. Just make sure it is large frame stuff (AR10) and not AR15. I believe the difference isn’t the extension but the buffer and spring.

This shit is spot on! My 708 WC rifle length needed the longer tube and the 18” barrel had a stupid small gas port I had to drill out. It works 100% with 120gr TTSX and Hammer Hunters. It runs a non adjustable gas block for those. I tried some 132 Hammers and I had some over gassing. I’d likely install an adjustable GB should I decide to go heavier from 120s.

 

[WindstormSCR]

Yeah, that's a good point, they are squashed. And even with the Lingle you'd be in less than a KAC or LMT (well, maybe).

The PMags are good to go, I should probably dump my metal SR25 mags one day, haven't had an issue with Magpul 10s 20s or 25s...yet

The metal KAC ones are still great to have for custom load lengths, as they can go to 2.85” load length for specialty reloads

 

[bigjake83]

I'm looking to put a 6.5 Creedmoor AR-10 together.
I've heard a few guys say the Ar-10 platform is prone to issues like cracked bolts etc. I'd never heard this so I'm looking for feedback from guys with high round counts.
I'm looking at building with all WC parts, any suggestions otherwise?
Also will 147 eldms be an issue for oal?

I've built hundreds of 'Home Builds" over the years same as @MSTN and I've never had any Issues with reliability or function, I've had a couple bad barrels but other than that no issues. All my builds run 100% reliable in any and all conditions.

You just need to have a solid understanding of how these machines work and what the best part selection will be.

99.99% of the time when it comes to Builds having issues It's from poor part selection and incorrect assembly.

If you move forward with a home build I'd be more than happy to coach you through it.

 

[762 ULTRAMAGA]

I've built hundreds of 'Home Builds" over the years same as @MSTN and I've never had any Issues with reliability or function, I've had a couple bad barrels but other than that no issues. All my builds run 100% reliable in any and all conditions.

You just need to have a solid understanding of how these machines work and what the best part selection will be.

99.99% of the time when it comes to Builds having issues It's from poor part selection and incorrect assembly.

If you move forward with a home build I'd be more than happy to coach you through it.

Thanks brother I appreciate that
I'll hit you up here shortly for some advice.

Thanks for not making assumptions, there's been a few posts about not understanding how to build or tune an AR.
I've built lots of ar15s from the 80% lower up, and I know what it takes to tweak the gas system for suppressors etc.

I thought long and hard about going 6 or 22 ARC but honestly the performance is weak in comparison, and cost is miniscule for a handloader.

 

[stevieb92]

HP in the large frame arena usually refers to a smaller firing pin hole to reduce cratering.

Correct. Usually the bolt will be marked with MP when it is magnetic particle tested after proof load testing. In the small frame arena, the HP marking refers to a proof load that was higher than normal pressure rating. This BCM bolt shows the markings on a small frame bolt.

https://bravocompanyusa.com/bcm-bolt-carrier-group-mpi-auto/

 

[BCP]

I'm looking to put a 6.5 Creedmoor AR-10 together.
I've heard a few guys say the Ar-10 platform is prone to issues like cracked bolts etc. I'd never heard this so I'm looking for feedback from guys with high round counts.
I'm looking at building with all WC parts, any suggestions otherwise?
Also will 147 eldms be an issue for oal?

Doubt it, you could run 143 or 123 if they are, 6.5 has tons of good bullet choices.

For building an AR10 the biggest thing is a properly headspaced barrel + bolt. With a 6.5 I would also run an adjustable gas block and a heavier buffer.

 

[wade2big]

Doubt it, you could run 143 or 123 if they are, 6.5 has tons of good bullet choices.

For building an AR10 the biggest thing is a properly headspaced barrel + bolt. With a 6.5 I would also run an adjustable gas block and a heavier buffer.

I use Toolcraft 6.5CM BCG. These are the ones with the double ejector and small firing pin hole. These have headspaced with WC, Faxon, Seekins, Rainier ultramatch, and Proof barrels. Checked with go/no-go gauges.

I’m wondering if the large frame headspace issue is blown out of proportion a bit. Regardless it’s always best to check headspace on anything if you are able even if it is just tape on the back of a live round or new piece of brass.

 

[CaptArab]

Some of the folks on here have built orders of magnitude more large frames than I, but in my experience of a half dozen or so and watching the forums for a few years the things that stump folks on the large frames are

1.) Trying to make a high back pressure can work. They really are significantly easier to get and keep running with a flow through can or bare muzzle.

2.) Silly light weight/ JP style parts. Just do the stoner thing with an a5 length extension (308 length, not mil spec ar15) and a standard sprinco red or armalite spring with a standard AR-15 h2 or h3 buffer.

I'd say > 90% of the "my large frame doesn't work" threads are due to

Couple those ingredients with the longest available gas system for a given barrel length (16" rlgs FTW) and you have the same basic recipe the big money contract guns run. It's really not difficult at all.

 

[762 ULTRAMAGA]

Has anyone tried this setup from Griffin armament? Purpose built for suppressed AR-10s
https://www.griffinarmament.com/griffin-ar10-stock-mounting-kit/

 

[stefan73]

I think some of the builders push the envelope for reduced recoil and better accuracy. Sometimes while pushing that envelope you will experience failure as a result. It is part of the learning process.

Just my .02 from tinkering

 

[CaptArab]

Has anyone tried this setup from Griffin armament? Purpose built for suppressed AR-10s
https://www.griffinarmament.com/griffin-ar10-stock-mounting-kit/

That's essentially the same formula I described above with a little pixey dust sprinkled on the h2 buffer. Seems fine. Would expect it to work great with a normal toolcraft bcg.

edit-
IF you grab a cheapo aero upper / lower, toolcraft HP BCG, this barrel (if you want 6.5), and (might not have to have it) sentry AGB, I'd bet good money your rig will shoot great with a low back pressure can like a hux

 

[viking78]

Buy a Seekins.

I would go for Seekins too.
Frankd did a nice review of the SP10M few years back.

 

[Vynz]

I’d say AR-10 rifles are problematic for a different reason - ideal use. As AR-15s continue to get more cartridges the volume of situations where an AR-10 is flat out a better option diminishes. With 6.5 Grendel, 6 ARC, 300 Blackout, and 458 SOCOM it’s possible for someone to keep essentially the same rifle, but have longer range, flatter trajectory, quieter hunting rounds, or a large thumping brush gun. The bar where one says “I need to step up to a larger sized, heavier rifle” keeps rising.

On the opposite end the higher power tier keeps leaving the AR-10 behind. The AR-10 was very interesting when everyone was living and breathing the 308win family tree as there was performance parity with bolt guns. But the AR-10 no longer keeps up; the 6.5mm PRS, 7mm PRS, 300 Norma Magnum, and many other “modern” cartridges won’t fit within the AR-10 magazine well.

I’m not saying the AR-10 as a concept is dead. I suspect it will continue to be absorbed into the AR-15 family through rifles like the SFAR and POF Revolution where 308win, 243win, 260rem, 6.5creed, 8.6blk and 338fed just become more cartridge options for “large magwell” AR-15s. But I do think full size AR-10s as their own separate platform like the SR-25, MWS, LR-308, AR-308 will go away.

 

[WindstormSCR]

I’d say AR-10 rifles are problematic for a different reason - ideal use. As AR-15s continue to get more cartridges the volume of situations where an AR-10 is flat out a better option diminishes. With 6.5 Grendel, 6 ARC, 300 Blackout, and 458 SOCOM it’s possible for someone to keep essentially the same rifle, but have longer range, flatter trajectory, quieter hunting rounds, or a large thumping brush gun. The bar where one says “I need to step up to a larger sized, heavier rifle” keeps rising.

On the opposite end the higher power tier keeps leaving the AR-10 behind. The AR-10 was very interesting when everyone was living and breathing the 308win family tree as there was performance parity with bolt guns. But the AR-10 no longer keeps up; the 6.5mm PRS, 7mm PRS, 300 Norma Magnum, and many other “modern” cartridges won’t fit within the AR-10 magazine well.

I’m not saying the AR-10 as a concept is dead. I suspect it will continue to be absorbed into the AR-15 family through rifles like the SFAR and POF Revolution where 308win, 243win, 260rem, 6.5creed, 8.6blk and 338fed just become more cartridge options for “large magwell” AR-15s. But I do think full size AR-10s as their own separate platform like the SR-25, MWS, LR-308, AR-308 will go away.

Probably the way things will go, but it might be interesting to see how the “Magnum Frame” ARs evolve, with more players entering the space thanks to the PRS cartridges leaving the AR10 behind.

Just not enough competition in the space yet to get a de-facto standard for the magnum frames

 

[B y r o n]

AR-10's are no more problematic than any other build. Do the research for proper parts before spending any money. Building it for mainline function is better than going the exotic route. Tested combination of parts is a plus over untested or parts you can't locate specifications on.

 

[mettee]

I think one of the biggest issues I see in the large frame gas guns are loads that exceed the pressure limits of the parts the rifle is built on. Creating an over gas or over pressure issue causing higher than "designed" bolt speeds will give you results you don't want. One instance is with or without a suppressor, another is ammo that is loaded too hot.

 

[45-90]

I don't run any suppressors, but I have no issues with AR 10s in any caliber...once set up.
Drill out gas ports and install SA gas block. Run the same hot loads as the bolt guns...adjust the gas block. I run the .062" Diameter firing pin and high pressure bolts, some with dual ejectors...as made for the 6.5 Creedmoor AR 10s. The 147s feed from the mag. In 6.5 Creedmoor.
Building a 510 Whisper this winter in bolt and AR 10...so as to go elephant hunting with an AR 10. The Barrel and reamer guys are slow, modified a 338 Lapua mag for it today.
Example a warm 308 target load, 200 gr SMK .715 BC, fired in 18" AR 10 2673 fps, was 2856 fps, from a long barreled 308 Win target bolt gun.
In 6.5 Creedmoor AR 10 24" barrel 150 gr SMK 2867 fps, 140 gr Nosler 2962 fps with RL 26.

 

[AZgeek]

I think one of the biggest issues I see in the large frame gas guns are loads that exceed the pressure limits of the parts the rifle is built on. Creating an over gas or over pressure issue causing higher than "designed" bolt speeds will give you results you don't want. One instance is with or without a suppressor, another is ammo that is loaded too hot.

After doing some research, this is why I elected to go with the JP full mass carrier regulation in addition to an the SA adjustable gas block.

 

[762 ULTRAMAGA]

Well I pulled the trigger on a Zev billet receiver set (exactly the same as a Mega maten just lighter).
I plan on going with a Criterion or McGowen barrel, still trying to figure out a bolt.
I'm considering the Toolcraft HP 6.5 BCG, RCA HP, or possibly save for a holy fuck expensive JP..

 

[Cascade Hemi]

Well I pulled the trigger on a Zev billet receiver set (exactly the same as a Mega maten just lighter).
I plan on going with a Criterion or McGowen barrel, still trying to figure out a bolt.
I'm considering the Toolcraft HP 6.5 BCG, RCA HP, or possibly save for a holy fuck expensive JP..

Lilja barrel, JP BCG

 

[45-90]

Well I pulled the trigger on a Zev billet receiver set (exactly the same as a Mega maten just lighter).
I plan on going with a Criterion or McGowen barrel, still trying to figure out a bolt.
I'm considering the Toolcraft HP 6.5 BCG, RCA HP, or possibly save for a holy fuck expensive JP..

The Toolcraft high pressure bolt with .062" firing pin is what I use on those high high pressure loads stated, (same as bolt guns) for 6.5 Creedmoor or 308 it works well, just add a SA adj gas block...so you can run light loads or those 65,000 psi loads in your AR 10.

 

[Charger442]

Well I pulled the trigger on a Zev billet receiver set (exactly the same as a Mega maten just lighter).
I plan on going with a Criterion or McGowen barrel, still trying to figure out a bolt.
I'm considering the Toolcraft HP 6.5 BCG, RCA HP, or possibly save for a holy fuck expensive JP..

What chamber extension are you going with? I guess criterion only sells dpms....

 

[762 ULTRAMAGA]

What chamber extension are you going with? I guess criterion only sells dpms....

The receiver set is DPMS so it'll jive with Criterion

 

[JR1200W3]

I highly recommend Proof barrels for LF ARs. They come with the gas tube so you know you have a matches tube. Proof has the gas length figured out on their barrels. Pair it with a JP bolt. If you don't want to buy their entire BCG. I have built two LF ARs and they were and have been drama free. Gas tuned within 10rds. I think the key to success has been builders kits for matched receivers. Matching of Proof barrels and JP bolts. JP SCS for adjustability in the buffer tube lengths and buffer weight adjustability. I've used SLR Sentry 7s for both builds. Lantac EBCGs are also really nice. I'm using the EBCG with a substituted JP bolt in the 6.5CM in a Proof barrel.

I used to be a big proponent of McGowen barrels but their quality of work on their blanks has slipped massively. I've received wrong orders and many folks here have gotten some pretty shitty chambers and muzzle threads. I recently thought their blanks were still at least good and ordered a .224 blank. Gunsmith just chambered it. When I picked it up I asked him what he thought of it. He cringed and said uncomfortably like he didn't want to tell me that the OD of the contour was not concentric to the bore. So when he indicated off the bore and then started spinning the barrel it was helicoptering all over the place. Haven't shot it yet.

If you don't want to go Proof, I'd suggest Rainier Ultra Match barrels. I would really encourage you not to skimp on the BCG and barrel. At least not the barrel. Consider a custom from CLE or Craddock.

 

[45-90]

I’d say AR-10 rifles are problematic for a different reason - ideal use. As AR-15s continue to get more cartridges the volume of situations where an AR-10 is flat out a better option diminishes. With 6.5 Grendel, 6 ARC, 300 Blackout, and 458 SOCOM it’s possible for someone to keep essentially the same rifle, but have longer range, flatter trajectory, quieter hunting rounds, or a large thumping brush gun. The bar where one says “I need to step up to a larger sized, heavier rifle” keeps rising.

On the opposite end the higher power tier keeps leaving the AR-10 behind. The AR-10 was very interesting when everyone was living and breathing the 308win family tree as there was performance parity with bolt guns. But the AR-10 no longer keeps up; the 6.5mm PRS, 7mm PRS, 300 Norma Magnum, and many other “modern” cartridges won’t fit within the AR-10 magazine well.

I’m not saying the AR-10 as a concept is dead. I suspect it will continue to be absorbed into the AR-15 family through rifles like the SFAR and POF Revolution where 308win, 243win, 260rem, 6.5creed, 8.6blk and 338fed just become more cartridge options for “large magwell” AR-15s. But I do think full size AR-10s as their own separate platform like the SR-25, MWS, LR-308, AR-308 will go away.

You can run a host of magnum cartridges in an AR 10 based on the 300 WSM or 300 RSAM neck them up or down even buy complete uppers. Most will be 6.5, 7 mm and 30 cal. Magnums... the limit is the magazine and its cut out dimensions. But it can be altered mine run 2.940" to 3.960" depending on magazine...and I'm on the process of building a 510 cal off the 338 Lapua mag case for the AR 10, close to 90 gr H2O capacity for powder...or more depending on your needs and any caliber 510 and below. Neck it to 7mm and have the same capacity as the 7mm Rem or Weatherby mag, in an AR 10, and it will hold the same pressure, 65,000 psi.