Back in Montana when I was teaching the club's concealed carry class it was at an indoor range with a concrete floor. I taught there was only one safe direction on the range and that was directly at the range backstop. The walls were concrete block and probably safe but they contained both windows and vents which were not bullet resistant. The indoor ceiling was a type of soft, sound-deadening panel material under 2x4 rafters and plywood decking that was also not bulletproof, so "up" was also not a safe direction.