I wanted others thoughts/opinions on CMMG. I was very interested in a Banshee until I watched a few videos with some issues with the Dissent and Banshee. I am sure this happens to others firearms but I just want anyone's comments who has had/has a Banshee.

Is CMMG quality?

https://youtu.be/3BmC-KgfzTY?si=yhw4pZSm_pNeF8fL

https://youtu.be/rwai59yw7Vo?si=pyZGxEfuJ0Ake6qY

my sample of 1.

my sbr banshee glock mag version was from summer of 2021.

first mag using endo mod and an sbr'd ar15 lower and the bolt extractor broke.

CMMG sent a new one and I can't remember if I added a BCM o-ring?
by this time, my cmmg banshee lower was approved as an sbr so i put it together.

mine is set up with the medium suppressor weight and an omega 9k suppressor on a 3 lug setup.

been running fine these almost 3 years using american eagle 147gr FMJ and OEM glock mags.


google amphibian threads on here, he talks about fixes for the banshee.
or i think his website was c3junkie.


it's been awhile, google amphibian on ar15.com or c3junkie.  He did a lot of work into the banshee fixes.it's been awhile, google amphibian on ar15.com or c3junkie.  He did a lot of work into the banshee fixes.

My Banshee in 45acp has been flawless going on 3 years now.
Added a Griffin Rev suppressor about a year ago, no issues except it's even more funner to shoot.

CMMG has earned a reputation of making good stuff but even the best of the best release something from the factory that can be a complete turd.  The more volume you make the more chance something slips out that does not work.

I saw those videos....
On the first one, I tried to post a comment to help them out but I guess they filtered me out and didn't want to hear it.  I don't know why he kept saying double feeds and failures to extract when clearly it was failures to eject.  The extractor did it's job in removing the spent brass from the chamber.  Double feed is when you have two live rounds trying to feed and I didn't see that in his video although was started to lose attention with all the misdiagnoses. So maybe some occurred later.  Myself and some friends have had CMMG RDB 'Banshee's since 2017 and we all have ejector spring failures.  We all run them full auto and suppressed.  I have extensively documented it on my site here: https://c3junkie.com/?page_id=221
I gave up went to a custom fixed ejector setup a few years ago but the issue still remains with the Banshee's.
The 9mm CMMG Banshee Radial Delay upper and the MEAN Arms Bearing delay both rely on ejector springs that are inline with the recoil impulse using a delayed system NOT locked like 556.  So they both take a beating.  I bought a MEAN Arms bearing delay and on my 3rd ejector spring in less than 2000 rounds.

The 9mm CMMG Dissent Radial Delay finally went to fixed ejector which is wonderful and works awesome but it is using a proprietary upper, no longer tune-able (and so not as smooth as a tuned CMMG Banshee) and no longer full auto capable.  I changed all that as documented here: https://c3junkie.com/?page_id=1733

I am very happy with my hybrid Dissent build now but as mentioned in my link above, I had to do custom machining to make it happen.
I stumbled on this video recently:
The guy puts the Dissent at #4 of all of the due to the lack of tune-ability and his 'wildcard' pick was actually my old CMMG Banshee setup I have documented here: https://c3junkie.com/?page_id=280
He claims that is the smoothest of all of them but it isn't listed as #1 since it using aftermarket parts as documented on my site.  My current hybrid Dissent build is even smoother than my old Banshee setup with even less reciprocating mass.


A quick video of my full auto hybrid Dissent build in action:

Thanks.  https://www.c3junkie.com

My CMMG Banshee in .45 is also fine.  I haven't seen anyone post about ejector spring failures in .45.  It is just w/ 9mm / .40SW and 10mm all of which are higher pressure than 45ACP.

I have a 9mm Banshee 9mm with extraction issues, I have emailed. CMMG, but have been little to help. I have pretty much given up on it for now. I plan on getting an Angsted

I did get an Angstadt MDP-9 (roller delayed) and one of the rollers sheared apart and deformed the locking piece.  Both of which are proprietary to the upper.  Took about a month to get the upper back and then I got rid of it.  It had less than 500 rounds through it at the time.  
Now I haven't heard of any issues with their UDP-9 (straight blowback)

I'm building a 9mm PCC for competition and I guess it's a Banshee for all practical purposes.
I bought a CMMG RDB barrel, bolt & upper and, purely by happenstance, I bought a CMMG Mk4 stripped lower for it.

I'll be using a standard carbine buffer & spring. Hopefully, it's reliable.
c3junkie's postings have been very helpful for me.

Amphibian helped me with my 5” .45 ACP Banshee.

I was having feed issues and problem repeated even after sending to CMMG for work.

Runs flat wire spring and Kynshot buffer made all the difference.

Biggest issue I have is POI shot when I mount the suppressor (Octane 45). 2” to 3” at 25 yds. And it is dependent where the cutout in then baffles is located so not consistent.

Considering going to an 8” barrel and see how that goes.

I have a 45 cal Banshee with 8" barrel for about four years now.  I stopped keeping track somewhere around 2,000 rounds.  I'm well over that now and have had no problems that were not cheap mag related.  No cool full auto like Amphibian though.

45 Super and 450 SMC run through it very well.  Glock mags are what it prefers for sure.  99% of my shooting is suppressed as well.

All in all a really nice gun for me.  I do have a spare bolt in stock, just in case.  Never needed to open the package.

Clearly, I've been happy with my 45cal version.