When i got my leshiy 2 .22 350mm it was way louder than any other airgun i have and i wanted to use it in my backyard without disturbing the neighbors so i modeled and 3d printed a baffle which reduce the sound from 95 db to 75 db. (long range accuracy not tested)
Up to 50m the accuracy is pretty much the same.
It significantly quites down the airgun and pretty much the air from cycling the magazine is the one i mainly hear when shooting.
Im currently working on different iterations in my spare time to maximize soud reduction and until now i managed to reach 71 db. I will do further testing then release an stl file for everyone to print if they are interested.