We have people who come to the indoor range where I am one of the RSOs that shoot .454, .460, .500 and .50AE. When the first 3 go off, the RSOs get real busy as everyone forgets what they're doing and step back to see what the heck just washed over them!
Very loud. And, on occasion, we shut off the lights (no windows on the shooting line of course) just to see the fountain of flame they emit. Very, very waaaay cool!
Congrats, Sledge. Just one question - doesn't shooting that thing upside down on the bottom of the Earth give you a headache?