I believe that the only true silent weapon is a firearm designed with a silencer function as an integral part of the weapon, not as an add on to the end of a barrel.
I used to shoot a bit with a firing device back in the late 70s - I believe that it was named an M1A firing device, and that was truly silenced.
I still have the manual back in a closet - I'll have to look it up.
I believe that the only true silent weapon is a firearm designed with a silencer function as an integral part of the weapon, not as an add on to the end of a barrel.