Around here we use skidloaders and dump trucks to build berms and then situate them where there is nothing behind the giant berm that can be damaged in the event, however unlikely, something makes it through the berm. The author's backstop is totally appropriate for a semi urban area or a place within close proximity to houses or people. It's ridiculous overkill on a decent chunk of land though. Even the range I train on with an instructor, which is not far from a couple other houses, isn't built with all that crap. It's surrounded by 15' berms.