I'm looking to build my own shooting range. I live in the middle of the country and I've talked w neighbors. This will be a 400 yd range, w individual steel bullet traps at every 100 yds. At the end of the range I'll build a berm for a backstop but what material will last the longest and what is most effective at bringing projectiles to a definite hault. I've heard tires, railroad ties and obviously a mound of dirt. The range I go to now has a 20 ft tall 15 ft wide berm w concrete blocks sitting atop the berm. I could easily find some fill dirt. I've got a bunch of dead ash trees that need cut down...could I use logs? Burying under dirt mound? Are there websites that help lead u in the right direction?