Well, building a gun firing range berm is out of our area of expertise! That said, we turned to expert Tom Gresham, host of the nationally syndicated radio show Gun Talk, for some sage advice:"On that question about building a shooting range, it's more complicated than the question would suggest.A great place to go for info on building a safe shooting range setup is the National Shooting Sports Foundation. www.nssf.org.If we are talking about shooing indoors, there are issues with air exchange and getting the lead in the air out and away from the shooters. There are protocols for cleaning the lead dust from floors and walls, also.If talking about shooting outdoors, the first issue is making sure it's legal to shoot there. Many counties have rules about this, so that has to be checked. It's smart to build the berm (backstop) higher than you think you'll need. It's absolutely critical that no bullets escape over the top of the berm. Many people have build private ranges on their properties, and it's a great way to go for shooting with family and friends. The NSSF can help on this, as can the NRA."