RE: Indoor Range, What to use as a backstop???
 

I don't know if your ever around commercial construction sites, but 2x4 acoustic ceiling tile works great. I own a construction companyand we replace a lot of ceilings, in factI will be throwing out a lot this next week, in Texas... I imagine you can call a dry wall company and ask when they are going to demo some they will let you haul it off. I would, it would save me from hauling it off...
They work awesome, lay them flat. when stacked high enough it's just like an indoor range.