A while ago, I got a slingshot and started trying to scare the doves away from my pool so they will poop somewhere else. It didn't scare the doves away, but it turns out shooting a slingshot is challenging and fun. It also scares the neighbors less than firearms or air guns.
The Problem: Lost Ammo
I can shoot the same airsoft BBs I shoot at the doves, but bigger ammo is much more satisfying (and results in less hand-slap from the bands). The bigger ammo isn't as cheap as the plastic BBs. At 80¢ each for .38 cal steel balls, it's sort of important that I get to shoot each one at least a few times before it gets lost.
The Catch Box
It's made from the cabinet that used to be my coffee shrine before I built a new one. I just stapled a towel to the ceiling inside it to arrest the shots. It already had a screw that used to hold a power strip in place, so I used that to hang an aluminum can from a wire.
Turns out an aluminum can isn't really a good target for a steel ball flying at a couple hundred feet per second. It gets sort of shredded after a couple of hits. Steel cans work better. They still look destroyed, but they actually hold up pretty well. This one has been hit at least a few dozen times.
The box is performing well. It traps about 1/2 of the shots inside. Another 40% can be found on the ground right in front of the trap. The remaining 10% get away and I have to go track them down, but none of them have made it 33 feet back to where I'm standing to hit me in the eye.