The form 4 finally came back for my 9k. I put it on my 9mm AR using a tri lug mount. It is a 4 inch barreled rifle. I am using hand loaded 147g FMJ over 4.3g of WSF. It is so loud that it sounds like there is no suppression at all. The can is rated for 300blk subs and supers as well. I used it on my blackout with 220g subs and it was very quiet, I tried it with 125g blackout supers and it was quiet enough to not need ear pro. With 9mm subs two shots and I needed to put plugs in. Next to me was a guy shooting a 9mm AR with an old SWR can and it sounded like a hand clap.

The only thing I can think of it seems that the bolt is cycling too fast now that the can is on it. THe bolt is coming forward and trapping the spent casing before it ejects out. Is it possible a heavier buffer would keep the bolt forward longer fixing the cycling issue and it make less noise out of the action as well?

I know very little about a pistol caliber carbine action compared to a rifle direct impingement action so what do you guys think?