If you go to your local office furniture supplier you can buy a metal stationery cupboard where the doors have been damaged. The one I bought is 6 foot tall and about 3 foot wide. I put an ordinary Bisley catcher on the shelves which give me low shots or level shots or high shots. The cupboard will stop a pellet on its own but I use old phone books etc to cut down on the noise. It cost me £20 quid delivered which is what the Bisley catcher cost. HTH
Tutchi