I know what you are going to say...

[Rotshout]

If this gets added, people are going to complain about it until Brass makes it terrible.

Building on your suggestion:

The Ventriloquist

Damage +30%
Accuracy +30%
Clip +10
Mobility -20%
Reload -20%

The only sound it makes is that of a skull imploding in the distance.
This rifle is semi-automatic and silenced.
The victims of headshot kills stand in place until someone moves them.