In 1883 he patented a new fully automatic machine-gun. An invention inspired by direct personal experience. Maxim's eureka moment came while at rifle practice with friends at Savannah, Georgia. The thumping recoil from his rifle was giving him painful kicks in the shoulder and he was getting tired of doing all the reloading himself. It occurred to Maxim to use one problem to solve the other. Could the force of the recoil be used to reload the weapon automatically?
Back at the drawing board, Maxim found an ingenious way to do it.
The key components are the barrel and the bolt. When a cartridge is fired both are forced backwards by the recoil, then the barrel is pushed forwards again by a spring, flipping out the spent cartridge. Meanwhile, the bolt is pushed forwards by another spring, loading and firing the next shot. Thanks to recoil the gun loads and fires itself with no outside help.
Now Maxim was in the machine-gun business. Hiram moved to London and unleashed a sales-offensive that matched brilliant engineering with flamboyant public-relations. A series of high-profile publicity stunts spread the news of the machine-gun around the world. Power brokers from all nations were invited to fire the weapon for themselves and one story, above all, became part of Maxim folklore. He claimed that his machine-gun could chop down trees.
Former special forces machine gunner Bob Pedesta aims to put this claim to the test. Using a 1916 Vickers gun, a British Army variation on Hiram Maxim's design, capable of firing 450 rounds per minute, he will attempt to topple a mighty Scot's Pine.
Having selected a suitable tree, Bob marked the trunk with white paint to serve as a target. Firing only short bursts to avoid overheating the muzzle, he began picking away at the tree trunk. After only 470 rounds the tree toppled.
Maxim's machine-gun was so effective during World War I that the basic design is still in use today. Maxim has quite a number of patents to his name, see his WikiPedia page for details.
CREDITS: The National Geographic Channel "Inventions of War" documentary series.