I found this link to be quite interesting
what liberals don't want you to see!!!
A acquaintance(name withheld) built a suppressors for a ruger.22 pistol, you barely heard a pop, and that's without sub sonic ammo.
I have a Savage MarkII LV bolt repeater .22 and when I use sub sonics its a faint crack. I couldn't run sub sonic out of my 10/22, it wouldn't cycle, and it was allot louder than my Savage, don't know why.
Anyway I thought this would be useful info, feel compelled to comment and to keep this thread alive so all can benefit