I'm using the reloadable shells that utilize a 9mm case to hold the powder in the high pressure chamber of the shell. Instead of buying the copper burst disks, I punch mine out of aluminum cans. My projectile is lathe turned by a friend out of nylon/some type of polyethylene. The front of the projectile is rounded and of bore diameter. The rear half of the projectile is a smaller diameter that fits inside the shell. The rear is hollow to provide more weight towards the front. They weigh 600 grains per my digital reloading scale.
Resize 9mm case. Prime with small pistol primer. Charge with 2.9gr Bullseye. Put a little tuft of paper towel in the case to hold the powder in place.
Insert 4 aluminum disks into the high pressure chamber and then put the 9mm case into the reloadable shell. The 9mm case rim will stick out of the chamber...that's fine, as it is of the right height to be hit with the RV85 firing pin. Insert projectile. Shoot and hope you can find the projectiles to use over again. Punch out fired 9mm case and start over.
The reloadable shells now sold use a 45acp case, so I suspect my 2.9gr Bullseye load might be too light. I kept increasing the powder charge and number of discs until the RV85 sound went from a "poof" to a "bang", and the projectile went from a few feet to flying down range.
I do have some other shells that either use shotgun primers and black powder or small pistol primers and smokeless powder, but have never tried them, as the reloadable shells using the 9mm cases seem easier and perhaps stronger. Have not tried making smoke or sparkle rounds, as I live on a farm and didn't want any fire danger, as the pasture is surrounded by woods. i also have a 12 gage adapter for firing shotshells and buckshot. The company the 12 gage adapter came from required a copy of my Form 1 before they would ship it.