I picked up a Diana RWS 34 Panther Spring Air Pellet Rifle.
I wanted to make a safe and silent home made pellet trap. I bit of searching online found what I need. Use Plumbers Putty as ballistic putty. A couple inches of this will stop pellets from an air rifle.
So, I wandered over to Lowes to pick up some plumbers putty. They where out. I drove to Home Depot. They had some in stock. I bought all five 5 pound buckets that they had. There was a run on Plumbers Putty in Lakeland that night!
So anyway, I also picked up a galvanized metal tray to put it in.
Here you can see what 5 shots look like. They penetrate about an inch and a half. They are stopped with less noise then the pellet rifle makes firing the pellet.
Here you can see what a pellet looks like when it was caught by this pellet trap.