I have been shooting at my back fence for the past several years. I finally decided to build a nice airgun range. I bought a 18×21 carport. It will take a few weeks for installation.
I'm going to build a back stop 6ft tall x20 long using 4x4s in the ground and metal roofing. I will have a small sand back stop to shoot into. The metal roofing will be to contain stray pellets on my property. I'm going to use a tractor trailer mudflap behind my stand up target stand. Don't plan on anything intentionally hitting the metal backstop.
I practice silhouette a lot so the front of the carport will be 45yds and the back will be 50yds.