During WW2 the Japanese built a deathray inspired by ideas from Nikola Tesla, the problem was that enemies would have to stand perfectly still for 10 minutes before it would work.
The WWII era B-29 bomber didn’t require fighter escorts because it had a computer aided gunnery systems that allowed incredible firing accuracy against attackers. One B-29 was attacked by 79 fighters at once, but was able to fight them off and down 7 of them in the process.
During combat, a US Marine’s rifle jammed, so he called customer service to help him fix it.
New Zealand’s first tank (the Bob Semple tank) was built from a tractor, sheet metal and 6 machine guns. When ridiculed for the design Bob Semple said “I don’t see anyone else coming up with any better ideas.”
Portuguese soldiers used black swords in the Age of Discovery in order to not reflect the light and announce their presence on ships, avoiding also its rusting when used near salt water.
Samsung has built a sentry gun which sits in the Demilitarised Zone between North and South Korea, which is hostile to anyone it senses who cannot provide an authorized access code.
A man in Shaanxi, China, recently realized that the long-handled, blunt-ended object he’d been using for 25 years to crack walnuts was actually a live hand grenade.
A Canadian inventor tried to create a “supergun” which could fire satellites into orbit from a 512 foot-long barrel embedded inside a hill. When Western funding failed, he turned to military application of his ideas for Saddam Hussein, but then he was assassinated in Brussels.
The Pentagon has rocket balls a.k.a. kinetic fireball incendiaries made of rubberized rocket fuel; when ignited, they propel themselves randomly at high speed, bouncing off walls, smashing through doors, turning an entire building into an inferno.
During the WW1 Germans protested against the use of shotguns in trenches by the Americans arguing Hague Convention forbid to employ arms that cause unnecessary suffering.