Not for you, @GRIZ, you can enjoy the laugh, but for everyone else including @JackDaWack & @ leahcim :
If you want to experiment with GSR, the easiest way to "trace" where it goes is to video yourself shooting the gun in question.
Different powder types burn at different rates (speed). Different manufacturers use different powders, and some are more "clean-burning than others (reloaders know this)! Bullseye is a dirty, slow-burning center fire propellant, NOT an explosive, and yet fills an indoor range with almost as much smoke as my black powder revo's seen here!
Easiest way I know of to demo GSR is to shoot a few cylinder's worth of the "Holy Black", then go home, throw yer clothes in a laundry basket and take a shower. Dry-off, then stick yer face a foot away from yer clothes and smell those glorious ROTTEN EGGS, lol! That smell is on everything you wore, RIGHT? That's the Poor Man's GSR Test, lol!
Rosey