eli5 Why weren’t machine guns possible to make in the past?

Question

What stopped 18-19th century armies with guns from being able to create automatic weapons like AK-47s and Uzis?
Since they don’t use electricity I feel like they’re made with materials and technology that was already available in the 1750s, surely they could’ve put their heads together to create a machine gun and just annihilate any ops…

Thanks

In: Engineering

Answer 1

Once bullets and powder were combined into one piece, machine guns weren’t far behind that.

Prior to that, each projectile needed its own powder to be added (per shot) to create propulsion. Once they were combined into an all-in-one package, it opened up the door to a whole new world of firearms.