I didn't want to derail this thread (https://www.ar15.com/forums/Armory/Dedicated-PCC-MPX-K-can-/20-549652/ ) so figured I would start a new one:
In that thread I mentioned that I wanted to try one of these out but noticed that the two Youtube stellar reviews by IV8888 and Sage Dynamics were used with the direct thread mount and that several people have posted that it doesn't sound good with the typical push / turn 3 lug mounts that like 99% of the manufacturers use.  I have mentioned before many times, that I consider those to be hit or miss.  I do have some that have given me no issues but they just are not as robust as the OG Bixler mount which is now for sale from Shaw Armament here: https://www.shawarms.com/products/thundercan-41182-11646-5176
I have no affiliation with them...just like Joe's stuff.  Recent thread on their Bixler mounts are also in this thread: https://www.ar15.com/forums/Armory/HUB-Tri-Lug/20-551280/

I do have an 'alpha' pattern Bixler mount on order with them but as seen below, I was impatient and made my own for now.

I put the title of this thread also Rad9 as it is my understanding the Cash9K is the same thing as the Rad9 in short mode?  

As pictured below the cyclic rate was about the same as my CT9KS which is large volume so didn't really see any huge reduction in back pressure compared to my CT9KS.










I liked it so much I made an UZI barrel nut mount for it yesterday.


Regarding the baffle orientation, the baffles don't appear to have anything to maintain a specific alignment which I'm confused about as I documented below.
I did send an email to Huxwrx this AM for clarification on their recommended alignment.  I did my testing with them alternating every 90 degrees as shown in the manual's picture not like the one my friend received at the bottom.


In summary, I am very happy with the performance especially considering the size and weight.  Again, not as quiet as my CT9KS or MK9K but also a lot lighter and shorter.  It is quiet enough that I don't feel like I need to grab hearing protection using it.  I also think there is a slight FRP but not excessive.

Great writeup as always. thanks.
If Im as lucky as my last form 4, I may get mine in the hands in 30 days.

What ammo/recipe are you running on your tests?

Just to confirm, this Bixler tri lug mount works with your everyday tri lug muzzle device?

Yes, and will be available soon as mentioned on my second link in my first post above.
They were invented by Tim Bixler (passed away).  The first and I think the best suppressor mount for 3 lug.  Patented in 1990 while the 'Latka' mount that most people use was invented in 1996.
Link on my site: https://c3junkie.com/?page_id=553
I need to revise this picture because you only need access to the rear of the mount if it is under a rail and the mount unscrews from the can.


See the other link I posted above discussing this where I have more pics and details on this mount: https://www.ar15.com/forums/Armory/HUB-Tri-Lug/20-551280/

I have been using the same load for 15+ years.  3.7Gr of Titegroup over a 147Gr jacketed projectile....yes I know max charge is listed as 3.6Gr.  One of the guys at the SMG match I go to loads to 4.0Gr of Titegroup so I tested going that high myself.  I didn't see any signs of overpressure but some were going supersonic here in FL so I decided on 3.7 knowing that if my powder measure drifted + / - .1 Gr it wouldn't be a disaster.
I use this load in all my 9mm pistols and SMG's.
The longest barrel that I 'typically' run suppressed is a full size UZI barrel that has been cut down and threaded for a 3 lug and is right at 9" and that yielded 946 fps.

Since then I now occasionally suppress a 11" FM9 Belt Fed upper and I can't remember if that goes supersonic.  I may shoot that today suppressed if anyone cares to know the results I can post back.

I also made this thread on the rimfire section: https://www.ar15.com/forums/AR-15/Fluted-barrel-CMMG-RDB--anyone-want-to-predict-the-results-/15-786110/
This is still a work in progress as discussed in the link above but figured I would post here as using the Cash9k.  My initial intent for the Cash9K was to use it with the BRT handguard for the short SD look with it tucked under the rail.  I was initially going to make a custom RDB barrel like I have been doing (discussed on my site here: https://c3junkie.com/?page_id=1882 ) from a SS straight blowback barrel then adding a 3 lug but then came up with this crazy idea of just modifying a fluted MP5K CHF barrel instead.