Original: About the time of the introduction of cartridge, breechloading, and multiple rounds of ammunition just a few years later, the term "rifled musket" gave way to "rifle", and "musket" fell out of fashion.
Simplified: A few years later, the use of cartridges, breechloading, and multiple rounds of ammunition meant the "rifled musket" gave way to "rifle", and "muskets" were no longer used.