Dolt needs help thinking it through here:

1) There are 3 patterns of 308 upper receivers: Knights Armament SR-25, Armalite, DPMS.

a)The DPMS comes high and low. ARG.

b) The most popular current pattern today is??? DPMS high?

2) The buffer tube, gas-port, adjustable gas block balancing act is where the 308 build gets pricey and in need of learning from other's mistakes. Right?
a) Get syrac linear adjustable gas block, (gen 2)
b) Get heavy buffer and compatible spring

3) Most brands of stripped upper receivers and lowers are OUT OF STOCK. So you might as well GIVE UP NOW! HA!

4) What pattern is the PSA 308 upper?

For starts...

Thanks!

Links appreciated mucho.

I guess these fellows are on the right track:
https://thearmsguide.com/8736/building-308-ar-rifle-works-compatibility-explained/

https://thearmsguide.com/8738/building-308-ar-carbine-works-carbine-compatibility-engineering/

https://docs.google.com/spreadsheet...0rW47o2PYbGiJM/pub?hl=en&output=html

I tried to cut and paste the compatability chart but it did not post cleanly and readable.

Robert, The South Shall Rise Again!

You gave up on the idea of just buying a complete gun? These things are in my opinion a lot more difficult to build than a 5.56. However knowing what I know now the MP10 was a pretty good gun, considering weight, reliability, not tack driving accuracy.

I'm anxiously awaiting Aero Precision's M5E2 (Gen2) upper to be released. If it doesn't suit me I'll probably go with a Mega upper/lower combo. From there, probably a Krieger barrel, JP BCG, SLR adj block, etc...

The most common receiver height is the DPMS "high"

To make it easy, go with a Vltor A5 receiver extension, standard H3 buffer, Tubb AR-10 recoil spring, and Syrac or SLR adjustable gas block.

I would respectfully submit that you need to know what you are buying, the current production for the majority of the DPMS patterned uppers available in my area is the low. The high went out of production pretty fast after the design change in 2009 (?) with the trend towards light AR builds, JMHO.

Robert, here's a link to the two types:

https://troyind.com/sites/troyind.com/files/rtc-attachments/DPMS_RECEIVERS_COMPARE.pdf

The PSA .308 parts are DPMS patterned.

Keep watching the Aero website, I picked up a .308 upper last week. They had a pretty good sale over the 4th of July, and the inventory is just now coimng back on line in their web store.

HA! I was going to get that Armalite AR10T-18 but after that gay bar shootout in Florida they all dried up. And the M&P10 too. I had a lower I bought on a lark just to have one so I thought I would do the build. But man! It is really confusing. Now it is turning into a grudge match inside my head; I gotta figure it out or die trying... LOL You know how that goes.

Last week? THAT WAS THE ONE I WAS GONNA BUY! I just gotta laugh. I have burned up an hour and a half of long distance minutes waiting to get through to Aero on one order they could not finalize and I was watching the 308 upper on the website day by day. Then it was in stock! I ate dinner and got my CC to do the order and then it was OUT again! 1.5 hour window of opportunity! HA! Just gotta laugh! YOU BOUGHT MINE! HA!

But seriously...

Thanks for the feedback.

Thanks a million.

Three days ago Aero told me they had 44 M5E's in stock. I would have bought one but I was not clear in my mind what rail/guard was congruent and they could not quickly explain. I got the impression, (and I could be wrong) that the M5E fit to handguard is proprietary. If anyone knows better please let me know.

I was altogether ignorant that the ones coming on line the end of this month were Gen2. The Aero website can be frustrating.

Here is the thread with the parts list on one I just put together and very happy with.
https://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/11192760/Re:_Bit_by_the_308_bug#Post11192760

Rifle length gas system, 12" rail, gas block un-covered.

Nice write up. Thanks. Seems like you veteran builders go with the rifle length gas.

PSA is DPMS low style. The PSA upper will work on some other DPMS style lowers but you need the PSA bolt catch. The PSA upper is forged most companies use billet on 308.

Yep. The more time the bolt is in battery while the bullet is in the barrel, the better.

Robert,

The "E" uppers do use the Aero handguards. If you look at the pictures you can see they don't have standard threads for a regular barrel nut, but have a mount for the handguard. That mount actually has female threads and a proprietary barrel nut that has male threads. This video will sort of show you how that works. Skip ahead to about the 2 minute mark to get through all the useless crap.

https://www.youtube.com/watch?v=cAEBXpHnHkY

So that leaves you to decide whether you want to use Aero's handguard or you want something different. I'm gonna get a good look at the Gen2 before I buy anything. If not impressed, I'll go with their standard M5 upper and add a different handguard. Or maybe just go with a Mega receiver set.

Hope that helps clarify. I've been studying up for a little while now, asking questions, learning as I go hopefully.

Aero makes two versions of the M-5 upper. One has an extension on the front of the receiver for their M-5 rail, they call it the "Enhanced". The other version is "normal" with the threaded extension, like you would see on any standard upper receiver. The Enhanced comes in their 5.56 uppers as well.

I have both, and either will shoot for you.

You can buy the M-5 rail separate, but they will ask you what type of upper you are using.

For a standard upper, the M-5 rail has a round barrel nut pretty much like any DPMS rail.tube, etc. The rail slips over the barrel nut and attaches with screws.

For their enhanced upper (with the rail extension), the barrel nut is proprietary, and goes into the extension under the M-5 rail. The rail attachs to the upper extension rather than the barrel nut.

^^^^^^^^^^

A better explanation. Well said AH64guy. The more I think about it I may just go with the standard model. There are plenty of rail options out there. Some that I like a bit better.

Yup. Because their upper and lower receivers are forged, they're also some of the lightest available. I like them a lot more than the factory DPMS stuff. 308 AR rifles don't have to be heavy.

Thanks everybody for the feedback; I cannot express how helpful this is in clearing up some confusion. Thanks a million.

M5 .308 Assembled Upper Receiver - Anodized Black
Product Sku: APAR308503A
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$155.00
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HA! Aero keeps sending me the notification email that the M5 is back in stock, but then it ain't! PSA is sold out. Buds guns is sold out of 308 auto-loaders (the armalite and the MP-10)

MAN! Everybody wants to fling 308 boolits these days.

If anybody has a link you stumbled upon, (and you are willing to tell!) for an upper in stock; please let me know.


UPDATE EDIT! AERO HAS M5 308 UPPERS IN STOCK RIGHT NOW.

I think SLR has the most and best options for free float hand guards that I can find.

I talked to a fellow at a gun show last month who built a PSA 308 and he had a LOT of problems running into road-blocks to finish it. It seems you have to use proprietary PSA parts for this and that.

Somebody ought to write a book on building AR10's and DPMS pattern 308's and make some kind of chart to splain it all.

All in all I like Aero Precision; even if you have to wait for stuff to get on the shelf and wait wait wait to talk to a rep on the phone. It seems like really quality stuff.

Ruger SR762 1650 cash and your done

ALL of the 308 AR configurations require some proprietary parts; PSA is no different and no harder to put together, if you pay attention to what is needed.

I like the PSA because they have the lightest receivers, and are closest to AR15 pattern.

I do believe you be right! LOL
Too late; jumped in...