Here's a WWII US M2 flamethrower in action

WOW. Two things to mention here.

One: This is a WWII-era flamethrower that has seen some upgrades and multiple service deployments in different wars over the years. It still works. And it is crazy powerful.

Two: The channel that uploaded this video is quite amazing. It's called Forgotten Weapons and it has a bunch of videos of old, weird-looking guns.