Well, after demonstrating a number of concussive firings I found that the cardboard
cylinder that a household abrasive cleaner is packaged in is just under the correct
bore, caliber 73mm or so. On my first launch out of my shorter "gun" I shot
the comet cylinder a good 4m and over a wall. It hit a palm. Very cool! Reminds me of the first beer-can shot with my first tube, surprisingly good results. Nice parabolic arc. Harmless fun.
I'm also experimenting with pure butane from an ITAWANI cartridge, which is a japanese thing. I like unusual (to me) food; I go to Mitsuwa, a japanese grocery in Costa Mesa, when I can. I always get fried squid, and either a bento or a sashimi & rice dish they have. Usually I take it back and eat at my desk. Anyway, cylinders of butane for small stoves are pretty cheap there.
Actually, hairspray seems to be best. Its probably the isobutane propellant.
