Good to know that!
Fortunately I almost never shoot them from the launcher. Much more fun to set them off on the ground. (Lots louder!)
The Salute to America shells leave a trail as they ascend from the launch tube. They are also *much* louder. (Hard to believe, but it's true.) The concussion at anything under 10 yards is not exactly painful, but certainly uncomfortable. As for your ears, they're deafening at that range. My ears rang for a good 30 seconds after I set off the very first one on the ground (at a range of about 6 yards). Big mistake!
I don't like to throw them by hand at all. If one were to have a lighting fast fuse and went off in your hand, you'd be left with nothing more than a stump at the wrist. They're really that powerful.
Adam