slingshots are deadly when used properly
I've been using them since I was a kid. I have two very excellent slingshots with spare parts and a few sizes of steel shot. They are silent and effective. Quieter than my suppressors, except for maybe my .22 suppressors on my .22 rifles. Pistols still make a bit of noise.
I used to use a 6 foot homemade blowgun too, with homemade darts. That thing was scary accurate too. I remember my first shot with that thing. I took out a squirrel with a headshot as he was on the run.