Look, we know that sometimes, Arnie just needs a really, really big gun to rock. But there comes a point where weapons just get too damned big. And I'm talking stupidly big. 4-foot handgun big.
Someone, somewhere in 1950s USA thought "Hey, I know what would be a great idea: a bazooka that fires a small nuclear warhead". Great plan guys. Technically, it was a tactical recoilless rifle, capable of being carried by infantrymen and deployed on the front line of the Cold War. The warhead bolted onto the thing was a W54, a puny little runt of a nuclear device, but still the same explosive power as 10 tons of TNT. And people fire this thing with a puny little recoilless rifle. Right. Want to guess how much money the US government pissed away on this little jolly? Half a billion dollars.
Yes, this is a one-off. And yes, it's wildly impractical. But who cares, it's a giant copy of a classic revolver, and it actually fires. The cartridges it burns off are 28mm rounds, bigger than used in a lot of conventional anti-aircraft guns. No one could accuse you of not bringing a proper gun to a fight if you rocked up with this.
I think, among other issues, Hitler had some kind of inferiority complex. All throughout WWII, he encouraged the construction of bigger and more phallic weapons. They all culminated in this: two ABSOLUTELY GIGANTIC railway guns. They fired shells that were 31 inches wide, and taller than a person. Think two dustbins stacked on top of each other and you're in the right sort of ballpark. The railway gun did see brief service at the siege of Sevastopol, where it destroyed a whole bunch of stuff, most notably an armoury shielded by 30 metres of sea and 10 more metres of concrete. Overkill? Yes, just a tad.
Metalstorm are a crazy Aussie company who produce weapons that are fired using electromagnetic pulses rather than those old-fashioned hammer malarkey. This allows them to stack multiple projectiles in a single barrel, and to fire them with ridiculous speed -- they also have a machine gun that can fire at the rate of a million round a minute. Anyway, this is a multi-barrelled grenade launcher that can fire 40mm high-explosive grenades at a rate of 3,000 a minute. That's quite a lot of metal flying towards you.
Another entry in the "superpowers competing to see who's got the biggest dick" column is this, the world's largest conventional bomb. It's officially called the "Aviation Thermobaric Bomb of Increased Power"; it's a thermobaric weapon that detonates mid-air, using a supersonic shockwave and high temperature to inflict shitloads of damage. Or, as one Russian general eloquently put it: "all that is alive merely evaporates". Moral of the story is, don't piss off the Russians.
There are rifles, there are big sniper rifles and then there are stupidly, pointlessly over-powered anti-material rifles. This is the latter. Designed for either putting massive holes in people, or small holes in vehicles, it has recoil like being kicked by a small elephant.
If you want the king of all over-powered weapons, this is it. This Soviet nuclear warhead has created the biggest bang ever seen on Earth. I could say it has a yield of 100 megatons. It would creates absolutely massive crater, and probably kill everyone with radiation. But that's all just words. Nothing, not even the video above, can really explain the size of the explosion that this would produce. Suffice to say, we'd be in some serious doo-doo if it were ever used in anger.
Lovingly known as a "siege mortar", the Little David was a weapon built by the Americans during WWII. Truth be told, there's nothing at all little about a weapon that fires a shell almost a metre wide, and weighed over a tonne and a half. Thankfully, it never saw combat, and, along with a bunch of other US WWII monster projects, got quietly killed off after the war. Thank God for that.