Even Eagle Creek range had rounds "escape". I shoot at Atturbury often, and I don't think a round could escape (never laid prone though). That's the kind of features these ranges need to have. But, that level of construction on a 500ft (goole map measurement) rifle range is cost prohibitive. It doesn't matter how high they build the berm, some derp will send a round over it. Arresting those rounds is the key.