howdy. I just got here, and i'm late, so don't know if this has been cussed or discussed,but NONEL brand lead-in works great. If you know someone who is a shooter in a coal mine, they cut off what they need, and throw the rest out. Grab it! There ain't a cap on it any longer; just the plastic tube with magnesium powder. Stick it in the touch hole, and use a pistol primer to ignite it. Just stick the other end in the barrel of your pistol and snap the cap. Fire goes thru the tube and KA-BOOM! The cut-off NONEL pieces will only keep a short time, unless the ends are stoppered. No longer a shooter or miner, but was in the right spot to get a bushing big enough to make a 3.75" mortar. Still got it, and could use some info, so I'll be trying to catch up , but why make cartridges out of foil? Wouldn't a piece of pantyhose work better? Doesn't the foil stick in the vent? And has anyone else used pistons with rings for a projectile?