LOL! I generally assume the media wouldn’t know a bullet from a cartridge if they had to swallow it. They use the terms interchangeably.
At least the AP Style Manual has a whole section on firearms to clarify such terms. Having a special section (for their reporters to ignore :-) does make it rather obvious how few in the media are familiar with such a topic. I guarantee that when I was an editor, though, this error was never made in stories I worked on!
Or, "on which I worked." ;-)