2 4X4 posts dug into the ground. A backstop of P.T. lumber, 22" X 40" wide, 4 layers thick. Rear layer is 2X8's horizontal, followed a layer of 2X6's vertical. Then repeated two more layers. Each layer screwed with decking screws. Thats room for three paper targets stapled side by side but spaced apart.
Roundball rarely reach beyond the face of the third layer. When it gets too shot up, say 150-200 shots, I unscrew where needed and replace a board. The lead falls out and is easily collected.
Helps being in construction and I can get all the sizeable P.T. scrap I could ever use for free. The 125 lbs. of lead I play with gets cleaned up and used over and over again. I'll never have to scrounge new lead again.