It doesn't matter how great some weapons seem on paper - sometimes, stuff just happens and even the coolest, most badass weapons end up relegated to the White Elephant chapter of history. Often times, these weapons that never saw action get caught up in political quagmire, or show up in the wrong place at the wrong time, with no war to fight.
Other times, in the greatest stroke of irony, some of the weapons that never saw action were just too great for their own good. Too big, too powerful, too expensive or just too over-the-top to prove practical in battle. But no matter what ultimately kept them off of the battlefield (including peace), it's hard for military hardware enthusiasts to not feel a little pang of regret at the idea of these great machines winding up in mothballs.
Vote up the coolest weapons that never saw action below, and be sure to let us know what you think in the comment section.
Horten HO 229 "Bat"
No, that's not a B-2 Spirit stealth bomber - its the German wonder weapon that inspired it. The Bat wasn't just incredibly fast and futuristic; it was the world's first purpose-built stealth aircraft. Most historians agree that the War could have gone very differently if the Bat had actually entered service earlier in the war, not least of which because of its planned big brother. The "Amerikabomber" would have been capable of reaching New York or Washington from bases in Germany, slipping under our radar, dropping a few tons of bombs, and returning without refueling. The original Bat, though, would have been more than sufficient to rain havoc all over Europe, Russia, and England with near impunity.
Excalibur Space Laser
Otherwise known as "The project that bankrupted the Soviet Union," this space laser was at the heart of the 1984 "Star Wars" program touted by Ronald Reagan. It harnesses the power of a small nuclear blast to create a concentrated blast of X-ray or infrared energy at the Earth. That might sound like a Doctor Evil doomsday weapon, but this laser was meant to prevent doomsday for the United States. It was designed as part of a missile defense system, and would have been used to shoot down incoming ICBMs while they were near orbit themselves. Technical problems, as well as the inability to target multiple warheads, kept this one from becoming a reality, but we could easily do it with modern technology. The air force is already working with airplane-mounted laser cannons to do exactly the same thing.
The $450 million awesomeness that is the F-22 Raptor has never once in its 25-year history fired a shot in anger. The world's first fifth-generation fighter has yet to find a target deserving of risking its expensive hide, especially since the Soviet Union collapsed. True, there are other fifth-gen fighters out there, but they're all still playing catch-up to the F-22 in terms of design and performance. And since it went out of production in 2009 (due for replacement by about 2020) it's unlikely this ultimate bird of prey will ever fire a single shot in battle. You could call that a shame, but as long as we're not using it, that means we're not at war with anyone dangerous enough.
Regular ICBMs have one major problem: They're easy to detect once launched, and leave the enemy plenty of time to shoot back. Any launch would essentially be suicide, which is exactly what kept either side of the Cold War from firing. The SLAM (Supersonic Low Altitude Missile) would have gotten around that by flying at mach four below enemy radar, using its nuclear-powered jet engine to travel more than 100,000 miles while irradiating everything it flew over, and leveling buildings with the sheer force of its supersonic shockwave. The SLAM's ability to strike without warning would have undone the mutually assured destruction policy, and almost inevitably driven the world toward nuclear annihilation. Rather than a nuclear deterrent, the SLAM was a nuclear provocation - which is the primary reason it never (officially) entered service.