The only barrels I've come across are from -

Stern defense
QC10
Shooting innovations
New Frontier

Macon Armory can convert some DI 10mm barrels to blowback with some dark magic, but I'm not sure that I want to have proprietary barrels.

Are there any other reputable companies making them?
Anyone have any experience with the barrels?

I've been running the CMMG RDB in .40SW for a few years.  It took some tinkering to find the right combination but it runs reliably for me in full auto and suppressed until the ejector spring dies at around 1K rounds.
Documented on my website below:
https://c3junkie.com/?page_id=854

OP....you can scratch QC10 off your list.
They no longer exist.

Personally.....New Frontier stuff is GTG.

I've used alot of their lowers/uppers/barrels/bolts in 9mm.
For a blow back style PCC, this is the way.


If you want a RDB system....cmmg is the one. More expensive.


Take your pick of the two.


FWIW....read up on amphibian's website for any other info you may need.





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Not interested in cmmg radial delay, ejector spring failures are not something that I want to deal with.

I've read through amphibians site multiple times.

Don't blame you.  I shoot 9mm the most and got so fed up with the ejector spring failures and now doing my hybrid Dissent RDB fixed ejector setup documented here: https://www.ar15.com/forums/AR-15/Ultimate-Full-Auto-CMMG-RDB-Fixed-Ejector-Project/15-785453/

For .45ACP, I haven't had the ejector spring failures and haven't seen anyone post about it either.

I think the CMMG RDB is great in the two configurations above.
I wouldn't use it for 10mm.

For .40SW, I don't shoot it as much as I did in the past and just keep an eye on the spring strength and as soon as I'm at 5lb's I replace the spring.  If CMMG ever comes out with a .40SW Dissent, I may do the same mods I did for the 9mm Dissent but not sure if it is worth it to me as I just don't shoot .40SW that much anymore.  I kind of doubt CMMG will release it in .40SW as well as I am guessing their .40SW Banshee may also be a slow seller.

Palmetto State Armory has this on Easter sale. Armalite AR15 PDW in 40SW. They have 9mm on sale too.

https://palmettostatearmory.com/armalite-m-15-pdw-40-s-w-9-33rd-pistol-black-m15pdw40.html