[4V50 Gary]

Or loudeners. I think one of my classmates is working on one for a joke. A former professional machinist (17 yrs), he can easily fabricate it too. There's only two reasons that justify such nonsense:

1) Clear the range so your buddies could shoot (I used to do the same on the pistol line with the Ruger Old Army back in my college days)
2) If you must in a self-defense situation shoot indoors, it would scare the begeesus out of the opponent (bigger muzzle flash to blind you and more muzzle flash to aim at for bad guy too).