Im currently putting together a SBR .308 off a Aero M5 lower.  I'm looking for a complete upper barreled 12/13 inches. Does anyone know any good sites stocking  any?

Google gives me a couple options for complete aero uppers.

https://vtsupply-com.3dcartstores.com/Aero-M5-125-Barreled-308-Upper-Receiver-with-Atlas-ONE-Rail-M-LOK-Handguard_p_5056.html

https://moriartiarmaments.com/ar-10-.308-12.5-aero-precision-style-upper-receiver-assembly-aero12.5ar10ur

Never ordered from either site.

Not sure what other options are compatible.

I'd build one myself with a stripped m5 upper if I was looking to use an m5 lower.

Actually, what i did was buy a (no longer available) 12.5" POF ROGUE pistol and sbr it.

Attached File


Attached File


Since POF doesn't sell a 12.5 gun anymore, if i was looking to do it now, if probably buy a 16" ruger sfar and have the barrel cut down to 12.5" (and obviously change the handguard, but they take ar15 handguards so take your pick).

There are still some newer 12.5's in stock but they shipped as a carbine, pinned with a fake can.

Now they sell a pinned and welded 13.75 model

You all made some good points. Buying a complete upper is just way overpriced when Im going to turn around and upgrade it immediate.. Found this M5 complete upper on sale that im just going to buy now so finding the right barrel will be all i need.

https://www.opticsplanet.com/aero-apar308503a-308-upper-blk.html?_iv_code=29D-UPR-APM5AUR-APAR308503AC

Schuyler

https://www.schuylerarmsco.com/march-sale/ar-10-barrels-56-993/125-308-cmv-barrel-carbine-length-4892934
$97

https://www.schuylerarmsco.com/march-sale/ar-10-uppers-20-993/blem-m5-308-assembled-upper-receiver-kodiak-brown-anodized-4649252
$194

https://www.schuylerarmsco.com/parts-gear/parts-gear/aero-precision-aprh308186-m5-bolt-carrier-group-308762-8620-steel-black-nitride
$249

can these barrels and uppers all shot 7.62x51 or only .308?

They will be fine in an ar10 shooting either 7.62 or 308

https://www.ar15.com/forums/ar-15/308_and_7_62x51/16-567875/

Ok perfect, thank you

So I think this set up will work...



https://www.gorillamachining.com/HITMAN-INDUSTRIES-AR-10--125-308-WINCHESTER-Barrel--4150-CMV-s--110-Twist--Carbine-Gas-System_p_596.html

https://www.joeboboutfitters.com/Kaw-Valley-Precision-Barrel-Extender-5-8x24-p/kvp-be-5824.htm

https://www.aeroprecisionusa.com/m5-atlas-s-one-m-lok-handguard

um... why are you going to put a "barrel extender" on it?

That can't be good for a suppressor if that was in the plan, but either way, if you want a longer barrel, then don't buy a 12.5" barrel. If you can't find the barrel length you want, then buy something longer and get it chopped and threaded.

barrel is shorter than handguard... hand guard width smaller than suppressor..

Then you need to buy proper parts that fit correctly not use a barrel extender. You are building from scratch why not use the right parts?

ok cool

Buy a different handguard. Or modify the handguard.

There are many handguards compatible with the aero m5 upper.

But adding a barrel extender is just going to be a headache for a suppressor likely resulting in baffle strikes.

If you get a non-enhanced m5 upper (like the one you linked on opticsplanet), it's compatible with any sr25/ dpms handguard.(dpms high)

Slr makes a bunch of options. But there are other brands as well.


Here's my 14" m5 pistol with a no longer available Daniel defense 762 handguard.

Attached File

ok I will just look for a 12inch hand guard then...


So actually this one will solve the problem unless i can find something else identical and similar in weight since the weight is also a big factor for me with this.

https://www.opticsplanet.com/aero-precision-m5-atlas-s-one-m-lok-handguard.html?_iv_handguard-length=12-in&_iv_code=29D-HZ-M5AS1ML-APRA538104A

Ok so this is what I parted together for my build...

I already have the buffer kit and LPK on order and plan to just upgrade to a since single stage trigger from PSA cheap.



https://www.opticsplanet.com/aero-precision-m5-lower-parts-kit-w-magpul-moe-sl.html?_iv_code=29D-LPK-M5APSL-APRH100974
https://www.opticsplanet.com/aero-precision-m5-308-carbine-buffer-kit.html?_iv_code=29D-BFA-M5308CBKT-APRH100158
https://www.opticsplanet.com/aero-precision-m5-atlas-s-one-m-lok-handguard.html?_iv_code=29D-HZ-M5AS1ML-APRA538104A
https://www.opticsplanet.com/aero-apar308503a-308-upper-blk.html?_iv_code=29D-UPR-APM5AUR-APAR308503AC
https://www.opticsplanet.com/silencerco-hybrid-asr-muzzle-device-46.html?_iv_code=1UL-BMB-SIHYA4-AC591
https://www.opticsplanet.com/aero-precision-apra700301c-charging-handle-m5-platform-black-7075-t6-aluminum.html?_iv_code=29D-CGH-APRA700301C-APRA700301C
https://www.opticsplanet.com/aero-precision-308-bcg-black-nitride.html?_iv_code=29D-BCG-APBCGBN-APRH308186
https://www.opticsplanet.com/aero-precision-gas-tube-mid-length.html?_iv_code=29D-RGT-APGTMDLNT-APRH100017C
https://www.opticsplanet.com/aero-precision-adjustable-low-profile-gas-block-w-aero-logo.html?_iv_code=29D-RGB-AGB1-APRH101614C
https://www.gorillamachining.com/HITMAN-INDUSTRIES-AR-10--125-308-WINCHESTER-Barrel--4150-CMV-s--110-Twist--Carbine-Gas-System_p_596.html

It says "12 in" but it's the same length as their other handguard.



SLR makes a handguard that will work



As does CMT




Wilson Combat also has one

If weight is a big deal for you on this setup, I would again recommend to actually buy a 16" midlength SFAR, pull the barrel, and have it cut it down to 12.5" or 13" (after submitting your Form 1). You'd likely be saving pounds over an M5 build, and likely $$$ as well, and you could throw something like an Aimsports  lightweight Mlok rail on it for $90 (or literally any other AR15 handguard).

It looks like you're planning to spend at least $1000 on this build. You could get an entire 16" SFAR + new handguard for that, plus another $75 for barrel work and end up with a sweet 308 12.5" sbr that weighs about the same as a 12.5" AR15.

If you've already bought some of the parts, it's likely too late to adjust course. But just make sure what you end up buying won't create more issues with you down the road trying to suppress it, etc.

If you're sold on that $100 hitman industries 12.5" barrel (never heard of them and the price doesn't inspire confidence, but...) the hitman website has what appears to be a similar barrel for $65.

Yea I literally just ordered that the 12.5 barrel couple mins ago so going forward with the plan.

I'm not really worried about the money as I long as I get what I want conveniently.

I already have the lower Form 1 approved so that's good to go.

damn so that hand guard is really the exact same size. *** Actually now that I think of it I have a plumber/mechanic neighbor who i can just git it to to trim it down to the perfect length.

Think all i would need now is a decent adjustable gas block option

The other barrel isnt threaded which means more work I don't care for.

Im confused.. I thought its said that that you cant use an AR15 handguard on a AR10??

You can with the Ruger SFAR  and POF rogue.

They are completely different designs than the traditional 308 ar guns. Truly an ar15 chambered in 308.

It's why I'm saying that option would be pounds lighter than the m5.

And i didn't notice the lack of muzzle threads on that other barrel. No wonder they are basically giving it away!

I see what your saying now..

The weight listed on that handguard isn’t accurate, Optics Planet fails to list the roughly 5 oz. for the barrel nut and mounting screws.

I’ve cut down/chopped more than a few handguards.  That is not a handguard that’s viable for chopping.  It has offset cooling vents and MLOK slots, meaning no matter where you chop it, it’s going to have some slot that’s now open at the front of your handguard.  That will lead to parts of the handguard being unsupported, significantly weakening it and likely resulting in bending/collapsing (eventually).  See how the red lines intersect either an MLOK slot or cooling vent?

Attached File


You need to find a 10”-11.5” handguard.  The PITA of it is there’s nowhere near the variety available in large frame handguards, so your options are limited.   12.5” barrels are even less common, so your choices are going to be even more limited.

Half-assing the handguard on an otherwise nice build with an SBR’d lower and a suppressor just seems like a stupid, short sighted decision, though.  That CMT handguard listed above is only $40 more expensive than the Aero.  If you can’t deal with the few extra oz there, the SLR is a bit more expensive but should be lighter than the Aero.  Either way, just do it right from the start.  JMHO.

Thank you but im going to stick to what I said.

If half-assing a rifle build is your jam, rock on brother.

Thank you... take care

Now that I have the .308 parts in hand ready to assemble, i run across this 8.6 idea and dont know if i should continue on with the current build and just build another 8.6 later if I have the motivation? or put the .308 barrel to the side and just get the 8.6 now. I already have an M&P 18" .308 so if wouldnt be a big deal to not have the SBR .308 but at the same time if Aero came out with a complete M5 builders set in a Burnt Bronze color I would def love to have the 8.6 in that rather than the .308

Also before anyone suggest it I live in MD so i cant buy the complete rifle.. wish they would just sell the complete upper

https://faxonfirearms.com/faxon-duty-series-12-big-gunner-8-6-blackout-pistol-length-4150-nitride-ar-10-barrel/

How effective is a can on these battle rifle caliber SBRs    ?

You don’t seem to have a lot of gas gun knowledge.  You’re trying to piece together a short barreled AR10.  AR10’s are finicky as is, even worse when in a short barreled configuration and then even worse when you try to use many different brands of parts. There is lots of great info here, there was a really good thread about AR10’s but it is archived now.  

You might be better off buying a complete rifle in the configuration you want.

silencers work pretty good and suppress well if they can take the beating

the issue with larger caliber short barrels is dealing with the amount of gas generated by the cartridge and the short dwell time.  semi auto's can be finicky to get running good but bolt guns are very nice , especially if you handload for it

ok so makes sense to stick with the .308 and look into building my first bolt action rifle with the 8.6.. i like that

I just bought one of the 12.5s. It was on sale so I said why not. Attached File

That's a great deal

For that price, after a tax stamp and gunsmith removal of muzzle device i bet you're still under what i paid for my 12.5" pistol back when they were available.

You may need a shorter handguard as well unless you run a linear comp or something.

Keep an eye out for the POF Rouge pistols. When the 'brace ban' was in effect, they were going cheap on Gunbroker. I kept missing out as I'd get busy at work and miss the auction end time. Gunbroker is a fishing trip, you never know what you are going to get. Many gun shops put their odd items on GB if they sit too long. I think a POF Rouge pistol is not a fast mover.

The heart wants what it wants, whether it makes sense or not.

IMO, SBR's should be in calibers that don't kick, for fast follow up shots CQB use.

The advantage of .308 is hitting power and accuracy at longer ranges. A short barreled .308 is not your friend at 600 yards.

A 12.5" 308 is either slinging same-weight projectiles hundreds of fps faster than a 16" 7.62x39 (125gr @2700fps vs 2350fps ) or much heavier bullets at about the same velocity for much higher energy and better ballistics.

It's not the answer to every question, but it's far from nonsensical. Especially with the newer light weight platforms.

The RUGER SFAR looks appealing. The dilemma of dropping weight in a .308 is an increase in recoil. After I built a 12.5” 6.5 Grendel I don’t even shoot my short .308s any more.  On short .308 bolt guns the weight of the stock, optic, bull barrel, and suppressor come into play but a semi-SBR really shines for maneuverability and fast target transitions.  Below about 16” the .308 seems mismatched unless the logistics environment demands it.

I'm the opposite. My 12.5" 308 Rogue has relegated my 10.5", 12.5", and 14.5" 6.5g guns to full time safe duty. Well, that and the evaporation of cheap 6.5g wolf ammo.

I've also had bad luck with 6.5g mags.

The 6.5g is definitely more manageable, but i threw on a limbsaver buttpad on the Rogue and the recoil isn't terrible.

I trust the 308 more as a platform for reliability (especially with mags), overall power/performance, and supply chain.

It doesn't hurt that out of a 12.5" barrel you'll be getting ~2700fps with a 130gr 308 or ~2400 with 150gr, compared to ~2300 with 120gr 6.5grendel from a 12.5" barrel.

ie more energy.

That said, with the standard large frame ARs the juice was not really worth the squeeze. I'd rather live with the drawbacks of 6.5g for being lightweight enough to carry around hunting or whatever than a bit of extra energy from a 308 that weighs a lot more.

But with the SFAR and Rogue, they now weigh about the same. So now it's just a question of recoil sensitivity and loadout capacity in my mind.


ETA: I'll also point out that i have a 12.5" 308 Rogue sbr as well as a 16" 308 Rogue. I'm not saying 12.5" answers every question, or 308 is always the best option.

But i think between 556 and 308 in various barrel lengths, most cases are covered.

A lightweight 12.5" 308 would be a worthy hunting or camping rifle for most scenarios, where it will be carried a lot and shot a couple times at most. No need for anything further than 300-400 yards in most such cases.

And with the Rogues, someone already loaded out for a short suppressed 308 rifle that's great out to a few hundred meters and functional even further, not to mention well suited for dealing with hard cover or approaching vehicles compared to 556 - would only need to swap uppers to have the 16" available to reach out even further.

You know... Should the situation ever call for such things.

Attached File

My go-to handload for my 12.5" .308 is a Hornady 150gr FMJBT over 47.2gr of Win 748 moving at 2515fps. I put 20rds of 168gr and 175gr FGMM through the same gun and got 2341fps and 2310fps, respectively.

Just wanted to put that out there for folks talking about short .308s and what they can/can't do.