In Revolution, episode 4, one of the militia guys says that they can't make bullets anymore. As far as I know, bullets were made before electricity. All that's needed is gunpowder, which the Chinese made a few thousands of years ago, and lead. I know that mass producing them would be difficult without electricity, but other than that, what would prevent anyone from making new bullets? Was there any further explanation given that I just didn't see?
The problem is that the specific bullets used in modern firearms do require electricity - not to mention certain alloys and chemical compounds which themselves require electricity - to create. So while bullets could doubtlessly be created without need for electricity, the modern bullets used in the modern weaponry that survived the collapse of civilisation shown in that awful television show would no longer be capable of production.
Theoretically, if you found all the correct materials already stockpiled you could fit them together to create bullets mechanically, but you could no longer produce all the components from scratch.
To be fair, that comment was likely just an example of the extremely shoddy writing on that show, rather than a legitimate observation.