Has anyone taken an AR-15 lower, placed an CMMG banshee 9mm upper on it and used the ar-15 mag with the 9mm mean arms insert and got it to run?

In theory it should work and I was looking to go this route, just wondering if anyone else has done it and what their experience was?

Thanks

Kinda.  These are not complete Banshee uppers, they are AR-15 uppers with the CMMG RDB bolt and barrel, same as the Banshee.  And the mags are CMMG 9mm, basically a P-Mag with a MEANS Arms insert in it that CMMG sells complete.  

Both run flawlessly.  The one on the top started as a traditional blowback 9mm a while ago.  I built the one on the bottom with the CMMG RDB and liked it so much, converted the other one, now same same.

Attached File

Yes. They run fine, until the ejector spring dies, which is a common problem with the Banshee design. I now have 3 Banshee uppers sitting here with no lowers because I went to the much better Dissent upper.  One or all of them may be getting rebuilt in different calibers.

Forgive the picture quality, I was showing my girlfriend the new CMMG stock that came today, with her Dissent upper on it and the new Mean Arms 40rd magazines.

How much longer do us common folk have to wait for our Mean Exomags?

I use a Banshee 9mm upper with the mag inserts on my select-fire lower quite frequently.  No issues.  I've put thousands of rounds through it and still on the original ejector spring.  

I also use the Banshee 45 upper with the Macon Armory .45 insert and mags.  I'd like to see MEAN make a .45 ExoMag for the simplicity of just using the standard magwell...

@AirborneCIB

I am still learning on these sub calibers, so pardon the simple question...

So a person can take the CMMG Roller Delayed Bolt, just drop it in to an AR-15 upper, attach an 9mm barrel, get the correct spring/buffer and that will work?  

If so, I am closer to getting this running than I thought.

Yes, but the 9mm barrel is the one CMMG sells matched to RDB bolt, not the regular blowback barrel, and it all fits into a mil-spec AR upper and handguard.  I don't like really short handguards. Here is the link:

https://cmmg.com/barrel-and-bcg-kit-8-4140cm-sbn-9mm

I run a regular carbine spring and buffer and it seems to tune well suppressed.  I tried a heavier 9mm buffer and it did not lock to the rear on the LRBHO, carbine buffer works great.

On my suppressed CMMG RDB in 5.7, I run a carbine buffer also.  The tech guy at CMMG said I might need a light buffer, but it runs great and the recoil in nice, lighter than the 9mm, so I left it.

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Thank you for the info AirborneCIB!

Which free float tube are you using in your builds?  I am going to try to do something similar where the forearm covers part of the suppressor.  I need to pick a suppressor to get the OD size so I know what ID the forearm needs to be first but it is always nice to look at something that works.

@amphibian

Aero Enhanced.  The one I built a while ago is an Aero Quantum, but that has been discontinued.  They fit my 1.5" dia suppressors.  I use Griffin Armament taper mounts on my PCC's, they seem to work well.  Never had one come loose, unless I remove it and that's with the handguard in place.

I preordered back in November and received them last week.

Don't know but I got mine last week as well.

No 'Roller's' in the CMMG RDB system.

Some info on the CMMG barrels on my site here: https://c3junkie.com/?page_id=1882

+1.  
I have this documented here: https://c3junkie.com/?page_id=221
Dissent is better in terms of reliability w/ the fixed ejector.
This guy did a good review of several PCC's.
In his review his 'wildcard' custom CMMG Banshee is running my OLD CMMG tuned configuration documented on my site here:  https://c3junkie.com/?page_id=280
In his video he says the Dissent is not as smooth as the tuned CMMG Banshee and I agree.


The Dissent uses a 99% proprietary side charging upper.  So....

1. you can't do an SD type build as the rail is too skinny to stick a can in there.
2. must use their side charger setup. Which I don't like
3. You can't just quickly swap to like a standard 556 upper since it needs that back plate to keep the proprietary recoil spring assembly guts from falling out.  Though, if you went all in on the Dissent line and got a 556 Dissent upper you could do a quick swap
4. Not tune-able anymore, there are some posts on Reddit where people are having issues when running suppressed with the Dissent in 9mm and .45.  The old .45 Banshee for example could handle .45 Super but the new Dissent can't do that since you can't tune it (CMMG posted this on a Youtube comment)
5. Can't run full auto or with FRT trigger with it's chopped carrier.

I addressed all the above by doing a hybrid Dissent build as documented on my site here: https://c3junkie.com/?page_id=1733

Have you run them yet?  Suppressed, they seem to get dirty fast and the follower hangs up.

Good timing.  I just got back from the range.  Ran them 100% full auto and suppressed.  
I was very skeptical they would work.  I only opened two of them and loaded them both to 40 rounds and just stripped them off by hand brand new, they seemed sluggish till it got down to like 30 rounds....but  to my surprise they ran very well even loaded to to the full 40 rounds.  I may even say 100%.
I say that because I was mainly using these projectiles from American Reloading.


I had a few FTF's with those projectiles but I have that problem with just about every mag...even curved Scorpion mags.
Now a few times I was able to run the whole 40 rounds in full auto w/ bursts w/ zero malfunctions even with those flat points.
I did try some round nose which fed fine.  So I'm inclined to say it was just these projectiles.
I am guessing at least 200 rounds put through these two mags today.  I am confident enough to attempt to use them at the SMG match this coming Sunday.  

\

I also tested putting one round in the chamber and then slamming a full 40 round mag in.  There is so much resistance pushing up on the bottom of the carrier that it wouldn't kick the brass out.  So at least in my configuration, I will most likely download to 39 rounds in case I need to do a tactical reload.

I think they could probably stand to have about 25% more spring power.   That alone would probably make it power through the follower hanging up like I was experiencing.  Probably a dozen times or so it failed to lock open on empty because the follower was stuck down about 1 round worth of travel.  I did only run 1 of my 10 mags, though, so it may be a fluke.  At least they are easy to take apart to clean

With the success of first two mags, I opened another 6 and loaded them all up.  Hand stripping rounds on full mags doesn't look good like the first two where the next round would just sit there for a second or two then move up.  I did load the first two mags to the max and let them sit for a few days before use so maybe that helped before live fire?
These things will be will be even harder to load with more spring power.  I use the bounce method to load them so it isn't too bad but can see a lot of people complaining about loading them.
I mentioned in another thread that I bought some of the Prepper Gun Shop Scorpion mags and those things were doing the same thing with rounds pausing before moving up.  Those just didn't work for me.  I also tried putting different springs in there to make it stronger, Colt, UZI and other Scorpion mag springs like factory Scorpion and the higher capacity AKV mag springs.  Even though they were clearly stronger and in some cases could no longer load to 30 rounds, the thing would still get stuck.  I even tried swapping the AKV follower into the PGS mag and still no go for me.