picked up a couple of M5 lowers cheap, standard lower, no stock, buffer/tube, trigger, pistol grip installed from factory.

Found several $400-$500 complete M5E1/enhanced uppers and regular M5 uppers with adjustable gas block, 16" MLOK.  From what I read, enhanced and regular uppers work with the M5 lower.

16" is what I want for both.  I see they have nitride options and for a few $ more, CMV/chrome lined options. I know the barrels are BA (I guess they bought them a while back?).

Anyone have experience with either re: accuracy?  I have a DD5v3 (16" DD 308) that has a magnified optic on it that I'd consider MOA'ish/accurate with good ammo, and these two are  getting 1-6 or 1-8 LPVO's (maybe a MPVO 2-10).  I do have lower expectations on accuracy given the price.  But, I don't want something that shoots shotgun patterns either.  I have a pretty good stash of M80 ball and then some wolf and tula junk that I'll use in these (match in the DD).  It will be suppressed the majority of the time.  If the hive says these are pretty good accuracy wise, for $400 (plus BCG/CH), I'm tempted to not mess around with building.

The other option is to BUILD the uppers, in which case I ASSume I need:
1)Aero M5 or M5E1 upper (requires aero enhanced handguard)
2)Can I use any 16" .308 barrel I want? (criterion, BA, Faxon, etc)?  any weird barrel extension?
3)if I go just M5, can I pick my barrel and handguard?

from what I read, the BCG from aero obviously work, but so do Toolcraft and a few others.  I'm definitely going with an adjustable gas block.

Oh, and I guess if there are other assembled uppers that will work on the lowers, open to that also.

Thanks!

I went with Aero M5 lower with Aero M5 complete 16" .308 upper since it was $395 on sale. I built out the stripped lower with my own stuff. (Basically a complete aero lower with better trigger and stock)


The complete upper has good accuracy, but it's significantly undergassed due to the small gas port on the barrel.

I had to replace the stock carbine buffer with a lighter weight buffer to get it to reliable cycle M80. I think the stock buffer is like 3.8oz and I replaced it with a 3.6oz buffer.

It cycled full power 308 ammo fine out of the box. It also cycled M80 just fine when I put my Huxwrx 762 can on it, meaning it was just barely undergassed.

I was getting around 3-4 MOA with winchester M80 ball, but when I loaded in the 168g Federal GMM SMK, it immediately tightened down to very close to 1 MOA. Same result with 175g Federal GMM SMK, go figure. With PMC Xtac 7.62 ammo it was around 1.5-2 MOA.


So you can get the complete upper and mostly be happy with it, but you may need to put a lighter buffer in it to reliably cycle lower power 308/7.62 rounds when shooting unsuppressed.


If you choose to build your own, I'd stick with an Aero upper just to guarantee it fits the lower. Lots of barrel options out there. Personally I like to stick Criterion barrels in my builds, but I've heard quite a few people in the community express satisfaction with their Faxon barrels.

Oh, whatever you do don't get the Aero handguard that has the interrupted rail on top. I think it's the S-One? The triangular shape of it traps heat and it gets really hot pretty fast.

My two large-frame ARs have M5 uppers (standard, not enchanced) and lowers, and Aero rails. Both have Faxon Match barrels. The 20" 6.5 CM gets me .55-.65" ten round groups at 100m, and the 18" .308 is a tenth of an inch larger.

I took the BA barrel off .308 upper as soon as I got it just cuz it's such a pig. It sits in my parts box. The BA that was on my brother's .308 (removed for the same reason) got just above MOA groups with Hornady BTHP. Not bad, could be better.

Barrel extensions for the non-Enhanced are standard DPMS pattern, so most anything will work.

Regarding bolts and carriers, most will work. My 6.5 has an RCA nitride bolt in an Aero NiB BCG and the .308 has the Aero NiB bolt in a nitride adjustable RCA carrier (RCA bolt has the narrower FP hole for 6.5). The 6.5 has an SLR adjustable gas block and the .308 the adjustable carrier. Doesn't matter where you're controlling the gas, just make sure there's an option to do so.



Agreed. My brother has that rail on his. I have big hands and like the larger diameter of the 'standard' handguards that attach with the four pairs of screws at the rear to the barrel nut. More ventilation and it keeps the hands further away from the barrel.

thanks!!!!  it comes with a carbine buffer - is it proprietary?  I thought it was short or something weird (don't have my hands on it yet).

re: barrel:  I may get one assembled M5E1 upper with either chrome or nitrided barrel and see how it shoots.  They don't provide much other than "16", 1/10 twist" so I assume it's a basic/rack-grade BA barrel.  It's going to get a mix of steel case and M80 ball, so I'm not expecting MOA performance, hopefully slightly better than minute of man.  It does not look like a heavy/bull profile though, maybe government profile?  I am also wondering if the CMV is worth the extra $30-$40 over the nitride.

regarding rails, can I use a geissele or MI with the standard M5 Aero upper?  Assume the barrel nut fits, etc?  It looks like Midwest has a specific rail just for "308 high profile" which is making me wonder about other manufacturers.

thanks again!

If I recall correctly, large-frame carbine buffers are shorter than small-frame due to the longer travel of the (longer) carrier. Other than that, the Aero buffer is not proprietary.

As long as the rail and nut are for DPMS high rail uppers, you'll be fine.

Not proprietary. I think it cost me like $15 or something for the lighter buffer. When I say it was undergassed, it was failing to strip the next round, but was ejecting just fine. So it just barely wasn't making it back far enough when shooting M80 ball unsuppressed.

I still hold it against BA/Aero though. In my opinion, any factory rifle should be gassed to shoot M80 ball with zero issues. The undergassing thing for 308 barrels has been a big complaint within the Aero community for some time now.

Love mine. Receivers, rail, lpk, adjustable gas block, and buffer/tube are aero. Carrier is Toolcraft, bolt is JP, barrel is Faxon big gunner 18” 308. Dead air brake, cmc single stage trigger, radian selector, Daniel defense charging handle, Trijicon Tenmile 3-18x50 in adm mount.

Pics are kinda dark, but here she is. I love this gun.

Attached File
Attached File

2) Yes
3) Yes

I would stay away from the enhanced because it limits handguard selection. That said, I went with the Aero Atlas R1 and I’m very happy with it.

It’s got steel irons, an 18650 light and tape switch, aluminum rail section, and a warne bipod hanging off it and it’s rock solid. It’s a heavy rifle and the 15” rail doesn’t flex under the weight.

thank you...I'll check out the faxon gun gunner options

appreciate everyone's input

That's a sweet rig.

I built mine, upper too, however I used a Criterion barrel instead of an Aero/BA model.

Everything else was Aero, other than the Magpul furniture, to be sure of functional compatibility Attached File


Sorry for the crappy pic, need to get a better one next time I have it out at the range.

The barrel is the main argument against getting a complete Aero upper. It's accurate enough, but that undersized gas port just causes too many issues. I fell into the "Holy crap it's only $395 for a complete Aero m5 308 upper!" trap.

Now I'm looking at spending $300+ to replace the barrel with either a Criterion or Faxon match grade.

that's exactly my debate.  there are numerous $400 - $500 complete (minus BCG and CH) uppers from Aero.  All are nitride or they do have some CMV barrel options in there also.  That's the easy route...

The alternative is a $195 upper receiver, a $200 or so handguard, then a $300-$400 barrel.  It may make sense to get a complete one with barrel, hope for the best, but know it may mean a barrel swap.

I'm thinking of doing an old school A2 stock and a quad rail if I can find one.  Aero stopped making theirs which actually looked pretty nice.  If anyone has any leads on one of those or quad rail recommendations for the M5 upper, I'd appreciate it.

Wise words. Only reason I bought a complete upper was because that was all that was available a few years ago. I would not have done so had I had the option to buy the pieces individually. The BA barrels are usually good. Usually. If you don't mind potentially having to remove the gas block and dick with the gas port, go for it. If not, get a better barrel and an adjustable gas block/carrier.

Interestingly, they have complete uppers, 16", nitride barrrel, WITH adjustable gas blocks for sub $500.

As previously mentioned, avoid the enhanced version or you are stuck using Aeros proprietary hand guard. I scratch built mine using Aero stripped upper and lower receivers, a 16” Wilson Combat barrel and Aero buffer kit. It too was under gassed. To function reliably I had to open up the gas port and use Slash’s heavy buffer and spring combo. It now functions perfectly with any .308 ammo I’ve tried.

i am probably going to buy one with adjustable gas block and then build one from scratch.

anyone know of a barrel that 100% for sure I won't have to open up?  I have a .750 Aero adjustable gas block laying on my bench now that I can use...

I've been looking at BA, Faxon, Wilson combat (comment above is steering me away).  Looking $300'ish or less.

Thanks

Neither of my Faxons had any cycling issues. The 6.5 with the SLR gas block is at setting '4' and I haven't had to touch that in years.

I went with a Criterion (18" rifle gas) barrel, no adjustable gas block and it runs perfectly, has since day one.

I also used the stock Aero M5 buffer and spring.

BTW, there is nothing wrong with using the Aero enhanced rails as they are very stiff and strong, excellent quality with one of the best mounting systems out there...but you do not need to use their enhanced upper if you don't want to, they can be used on any standard upper using their barrel nut, which I recommend.

@jd2395


Look here

There's 5 pages of aero parts

https://www.schuylerarmsco.com/manufacturer.aero-precision-993?page=2&manufacturer=101974

Schuyler Arms is a good place to get Aero parts, Arm or Ally also.

Here's mine.  I'm sure someone out there knows all the idiosyncrasies of mixing and matching parts for 308 ARs - I don't.  I went with almost all Aero parts except for the gas block (I used a RifleSpeed), trigger, suppressor mount, sights, scope mount and plastic furniture which is all MagPul.  I've had zero problems with it.  It just worked from day one.  I did spend a few months acquiring parts.  Barrel is 16".  It's chambered in 308 Win.