I fully agree on the loudness aspect of 45acp in that setup. I have a Mech Tech ccu for my Glock 21 and was surprised at the lack of recoil and how quiet it is, my wife can run it just fine.This is my current pcc home defense set up, except it's wearing a stock and an approved sbr stamp now. 45acp and it is definitely not going to damage my families hearing if i need to use it. It may not be 223, but i wouldn't want to be on the recieving end of this mini-thumper