Designing a range for safety is not rocket science. If you want to keep the range badly enough, visit other ranges that have successfully addressed safety problems and just do it. When one of my local clubs got a visit by the state cops one day concerning a stray bullet into a nearby home - I contacted the NRA about assistance and with all the hoops and $ the club would have to go through JUST to have get them to visit and make recommendations , I knew it would never happen with the real possibility of us loosing the range. I did my own research on-line, found military specs used for military base ranges ( minimum amount of sand/ soil to stop .223 or .308 or .50 BMG rounds, SDZ (surface danger zone= degrees of angle which determines the length of back stop), etc. I enjoyed doing the research and designing and building the safety barriers. I then used that knowledge to build safe backstops at my hunting clubs range.