Recent conversations in our forums prompted me to finally finish an article on creating a BB trap that I've been meaning to wrap up for some time now. While I personally don't reuse bbs at all, I know some do and this design not only collects your shots reliably but does so with the least stress on the rounds. It also makes recovery of the rounds very easy. Make your own call.
So with a little effort, an old pillowcase and a 5 gallon bucket you can mke your own trap that won't leave little fragments of cardboard all over the place.