What's the best setup I can do to mitigate the direct blowback recoil on a 9mm Colt Pattern lower with an 8" upper and standard weight BCG? I've tried regular AR-15 and AR-10 springs with different buffer weights but they didn't do much. Shooting this gun back to back with my MPX makes me hate it because the recoil in the MPX feels so much better. I don't expect them to feel the same after upgrading the buffer system but I know it can be significantly improved.

A friend I shoot with has a Blitzkreig buffer system in his 8" 9mm PCC and it feels much better. Is that the best I can do? I'm open to any recommendations, thanks.

Did you see this thread just a few posts down?  https://www.ar15.com/forums/Armory/Reducing-9mm-blowback-perceived-recoil/48-523644/

Also this: https://www.ar15.com/forums/Armory/PCC-recoil-instrumentation-Macon-Armory-works-/48-524112/

i have a qc10 buffer and bcg in my 9mm pcc

runs great