Not exactly what you are asking about but, as a possible data point..
I very recently have had the opportunity to use the CCI quiets out of a bolt gun on ground squirrels to 45 yards and they do kill pretty well. 22" barrel, report about what a light pellet gun sounds like, or a loud hand clap.
From the same gun the CCI SV is more accurate, though louder. It also kills more efficiently.
Again same gun, the Rem SV is by far the loudest.
The one I'm very interested to try is the CCI quiet segmented round.
