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

Before 1886 all guns used black powder. Black powder is very very dirty, it will cause guns to jam up after only a dozen rounds or so, making it impossible to use reliably in an automatic gun. People did try, the Maxim gun originally used black powder, but it would always cause jamming issues. After 1886, smokeless powder was invented, smokeless powder is much cleaner and allows guns to shoot much much longer before jamming. Smokeless powder also comes with the added benefit of being much more powerful than black powder. After the invention of smokeless powder, automatic guns actually became possible, and because of that you see their popularity explode from 1890 onwards.

Edit: Just want to add that the first gun to use smokeless powder was the 1886 Lebel. There were other important inventions before then too, like the self contained cartridge and developments in spring manufacturing. Smokeless powder is really the final and most important invention that finally made automatic guns possible.