I usually didn't shoot it at the indoor range but I had it with me and the range was slow. There was two other shooters and the RO. As soon as I lit off the first round they all came over and were Oooohing and Awwwwing.
I told the RO before I went in that I may fire off a few .454 rounds and he was playing it off like it was nothing. I don't think he really knew the BANG it gave off until it went BANG.