Last week my wife came home with a new flat screen TV for the bedroom. Being a good husband I dutifully hung it on the wall, plugged everything in and turned it on. Turns out it's wifi capable and has YouTube (gun videos in HD!) A couple days later I'm watching the NFA Review Channel and dreaming of the day I get my stuff out of my dealer's safe, she comes in and starts asking about what I'm watching and which suppressors I've recently purchased. I come clean about all of them, she's ok with it! Then she says "We should build a pistol range out back. Dig up a berm, build a covered shooting area..." So, how high should I be building this berm?