This is in 556. The Hera just got put on last night so I can't speak to it yet, hopefully it's less obnoxious, but I shoot strictly on BLM land so I honestly don't care much. No boomer range officers are going to call me out for being loud. My Geissele 8" build would get me kicked out of local ranges.

The KAK is an absolute demon on a 10.5" Aero CMV carbine gas length barrel though.

It's on an Aero Thunder Ranch lower, Aero upper, Aero S-One handguard, Aero carbine gas tube and block, nickel boron BCG, Geissele braided carbine length spring and H2 buffer in a mil-spec buffer tube with an SB brace. It honestly shoots like a rifle which is why I absolutely adore this thing. There's a good picture of it somewhere in my submitted.