The use of center fire primers allowed the reloading of fired cartridges whereas, rimfire cartridges, once fired cannot be reloaded.
By the way, there were, at one time, some internal, center fire primers that could not be reloaded. Things evolved, the fact that the center fire cartridges could be reloaded was a selling factor.
Due to the increasing cost of ammunition, there be no warning shot!
The growing federal deficit = generational slavery to the national debt.