We used to tape a straw onto a CO2 cartridge. We used a length of coat hanger drilled into a board as the launch guide. Then had a nail sticking up out of the board. With a little practice, the CO2 cartridge/straw was lowered down the coat hanger we, put the cap of the CO2 cartridge on the point of the nail, hit it with a hammer, and it went 20-30' up in the air. This was about the vintage of the "Red Ryder BB Gun", and nobody got their eye poked out. 8-)