Oxy-propane and air-propane mixes make a pretty good bang. It's used in commercial prairie dog, mole, and gopher elimination, for "cannons" to scare birds away in orchards and other places, as "light"houses (in the olden days) for maritime warnings, starting golf tournaments and sailboat races, and all kinds of stuff.
Arguably, the most common gas-air salute cannon for entertainment makes use of an acetylene-air mix in the "Big Bang" cannon which is still available:
In action:
https://youtu.be/NVBdEItnHGs (0:34)
The acetylene is generated within the cannon by the reaction of calcium carbide and water, just as in the old miner's "carbide lamp."
Terry
REF (Carbide lamp operation):
https://youtu.be/R_daYTJhqBQ (2:01)