Looking for some options for a 9mm AR15.  I had an ar15 9mm 5.5” SBR, sold it for a mp5 platform and years later sold that.   Looking now to reacquire an AR15 9mm platform.

PSA seems to have these for 500-ish in pistol form and I’m ok with that.  What’s abt the shockwave “non stock” vs the arm braces for fit, feel, weight?  They also have these in 5”, 8” and 10” barrels.

What’s the best mag platform right now?  Dedicated Glock mags?  Standard AR lower with a mag block (UZI/Colt mag)?

Old pic (Hahn dedicated magwell and colt mags)

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Tag for interest, especially after seeing this.

Holy fuck balls that's slick.

I was just going to post that.

The two big questions:

Do you want Glock Mag capability, and do you need Last Round Bolt Hold Open?

PSA makes one that is pretty good by most accounts, but doesnt have LRBHO.
CMMG Colt Mags

CMMG with Glock Mag

Angstadt Arms Glock Mag

Stag Colt mag 9mm...   Out of stock at the moment

Wilson Combat Glock mag compatible

Quarter Circle 10 has trigger upgrades free with their builder's kit

What do you want to spend?

Going cheap but functional on this one. Have plenty of Glock mags so leaning towards one of the 500.90 PSA guns. LRBHO isn't important to me.

I have 4 of the PSA guns. 2 colt fed and 2 glock fed. All work well. Aesthetically I like the colt ones more.

Freedom Ordnance FX-9....they run about $600 but take Glock mags and have a LRBHO device.

Spikes 9mm Glock mag lower. Built this on a budget. Spent roughly $600 (not including stamp and optic). Just about everything you see, except the lower receiver, I purchased used off the EE or I bought as blemished product. Took me nearly a year to acquire everything, but I was able to do so at rock bottom prices.

my USPSA PCC carbines are New Frontier and Palmetto State (same basic billet by NFA).... the PSA hand guard fits me well... I have additionally an NFA AR15 style bolt and extractor, and the PSAs have pistol style extractors... the primary has over 9000 rounds after an OEM firing pin break...I find it easier to reload a Glock mag during competition as the cut on the front of the mag well is the same angle needed to insert the magazine.... my SBR uses a Colt format mag block from Macon Armory... works well, but I've fine tuned the action of the competition carbine for reduced 145 power factor loads... I like the action of the Glock format, as the cartridge is stripped directly into the chamber without the need for a feed ramp.... playing with very short stubby 95 grain .380 bullets caused some reliability problems in a friend's Colt format carbine... and with an after market trigger and dot you are still pretty inexpensive with the AR9 (PSA)

PSA has a 7" barrel'd pistol (Glock mag version) for 499.00, free shipping. Normally it's 549, free shipping, but I've held off til now. Its been ordered...  

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I have nearly the exact same setup.

You will be pleased with it.

For sights I'd reccomend the spitfire. Works great on my 4" 9mm ar.

PSA pistol with brace, received.  Took it to the range, shot it 100rds or so, with 2 Glock mags and the included 31rd ets mag.  Gun was flawless.  Not a fan of the shockwave, so picked up a sba3 for 99.00 shipped.  Will be another net increase of 55.00 or so once I sell the shockwave, or I’ll move the shockwave over to my Ruger charger...

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You may be able to get a PSA lower right now, but it seems that they've been out of uppers for a while.

I wanted a Colt gun, so I got a PSA lower and ordered the upper from MAS Defense.
Add a brace, Spinta bolt and some sights and you are good.

PSA a lowers, uppers, and guns are good though.

I have a Spikes Glock lower with LRBHO and PSA upper with 4" barrel.  It's been reliable but I haven't shot it much since getting a couple Mp5 clones.  The AR9 isn't as smooth shooting as the Mp5 's.  

That's how I was as well. The SBR in my original post was from 2006.  Once I got a MP5 clone with sear, the smoothness of the roller lock stood out and I sold the 9mm upper and used the SBR lower for a different project.  Years later, the sear and 6 hosts are long gone and I'm starting full circle..  

Here's a review of the MEAN Endomag.

Brilliant idea, but the execution leaves a bit to be desired.

They need to make a more permanent modification.  A complete, more durable and permanent Pmag modification would be ideal, with metal ejector, etc...

https://youtu.be/L0lmtUDrKXQ

Has anyone looked at the Freedom Ordnance FX-9?

All the reviews seem to be excellent.

Designed from the ground up around the Glock magazine and given AR ergonomic.  The receiver is actually smaller than an AR15....

Even has LRBHO....

Any experiences?

I'm surprised nobody mentioned the CMMG Guard radially delayed blowback setup.
I'm running that in full auto with RDIAS.
Also have a full auto MP5 which I think is the gold standard for a closed bolt SMG in terms of smoothness.
I also have a Sig MPX with a post sample DIAS.

I still give the MP5 a slight edge over all of them in terms of smoothness.  But I'm not done tuning the CMMG Guard.

My current state is that while the MP5 is slightly smoother than the CMMG Guard, the MP5 is limited in regards to what you can do with it.  With the advancement in buffers, springs for the AR platform constantly evolving as well as the myriad of aftermarket parts I much prefer the Guard setup.
I'm using an A5 buffer, 9mm Blitzkrieg hydraulic buffer and 556 Tubb flat wire spring at the moment and it is very smooth.  You can see I have full auto MP5K PDW in the background for comparison.  http://c3junkie.com/?page_id=538

BTW, I have a buddy running the Guard setup on a PSA Glock lower, all he did was remove the ejector from the PSA lower and made no other mods to the lower.
Bought just the barrel and BCG combo direct from CMMG, using same buffer/tube/spring setup as me and using a RDIAS as well....so another option for you if want to keep using the PSA lower w/ Glock mags but want to get away from straight blowback, but still have the great AR ergonomics.

I am running the CMMG Guard radially delayed blowback.  You can see in the picture below the angled cuts on the bolt.


The Guard relies on the ejector IN the bolt just like how a standard 556 bolt works.  You can order Endomags with the ejector cut off or do it yourself and so all those ejector issues are not a problem with the Guard setup.  Picture below shows Guard endomag direct from MEAN arms where they removed the ejector.  Bottom is the Endomag that still has the ejector.



Here is a link to it running in full auto. https://www.youtube.com/watch?v=_XaGtM2NT38