What am I doing wrong with the fuel and packing I am using for a cannon I made? Recently I have been using flash powder in a cannon that I made, for a chemistry project, however, it is not causing the rubber ball I put in it to propel out of the tube. First I put in 30g of flash powder, then pack a small wad of paper on top, and lastly insert the ball in an aluminum foil bowl. The fuse is then inserted into the bottom and lit on fire, but the only thing that has been happening is fire flaming from the end of the tube and melting parts of the rubber ball. Do you have any small suggestions, as I am running out of time to figure this out? I attached a picture of the cannon. (Also I do not have time to make black powder).
Flash powder and gun powder are two different mixtures, designed to do two different things. Gun powder is designed to produce a lot of gas very quickly (Carbon dioxide, Sulfur dioxide, Nitrogen) which propels the projectile out of the barrel.

Flash powder - typically potassium chlorate/perchlorate and aluminium powder, examples here and here, produce a lot of heat and light very quickly but not much gas - so no propulsion.