can matchstick powder be used as a makeshift powder for bullet cassings

No, matchstick powder should not be used as a makeshift powder for bullet casings. Matchstick heads contain a mixture of chemicals, including an oxidizer, and are designed for ignition rather than propellant use. Using them in place of gunpowder can be extremely dangerous and unpredictable. It can lead to misfires, erratic performance, or even catastrophic failures, posing a risk to the user and others nearby. If you are interested in ammunition reloading or making ammunition, it is crucial to use proper, commercially manufactured components and to follow established safety guidelines.