I normally shoot outdoors unless I need to test stuff in a controlled environment. Last time I went to my indoor range was to adjust the gas control screw on my (brake equipped) SCAR 17. I had to check operation both suppressed and unsuppressed. I was courteous and warned all shooters about my gun. I still emptied the range FAST when I started firing unsuppressed. Still, as long as you warn everyone, you're just as entitled to the range as anyone else.