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

Assembly line and interchangeable parts is what made it not possible. Back in the 18th and early 19th this was not around and was just beginning to be a thing in the Industrial Revolution. Machining assembly lines for this like gun parts did’t start until the late 19th century, and interchangeable parts were not common until Henry Ford.