I think some of you need to do 2 things:
1 - Work the pits in a rifle match. (The sonic boom isn't *the* loudest part of firing a rifle, but it's very loud and hearing protection is required.)
2 - Go to a machine gun shoot and watch the tracers bounce around. They'll give you an education in range design. I can easily imagine a bullet doing a skip and tumble straight over a 25' berm and still be moving over 500fps on it's way back. The lower the berm, the lower angle of ricochets it protects against.
