The 10 Biggest Guns In History Ranked By Caliber

If a pistol is good, then a canon the size of a train must be great, right? Mankind has been building firearms for around a thousand years and ever since that first Chinese bamboo spear gun, we've only been building them bigger. If there's one thing we've learned over the years, slugging it out from long range, it's that size definitely matters.

Here are 10 of the biggest ever built ranked by caliber. 

Caliber: 420-millimeter
Origin: USSR
This prototype self-propelled gun with a comically long barrel spanning 66 feet was built by the Soviet Union in 1957. The gun could fire a 1,654 pound shell nearly 28 miles. The recoil was so intense, however, that it basically destroyed the gun’s tracked chassis. Also, that huge barrel made parallel parking quite a hassle.

Caliber: 450-millimeter
Origin: United Kingdom
This short barreled, rifled muzzle-loader lived up to its name (and more!) with a total weight of 103 tons. Though it was commissioned for the coastal defense of Great Britain from 1877 to 1906, its comparatively short range of only 3.7 miles made its usefulness subject to debate. Still, its 2,000 pound shells packed a serious wallop.

Caliber: 457.2-millimeter
Origin: United Kingdom
Built at the tail end of World War I, the BL 18 Inch Railway Howitzer was an imposing weapon capable of tossing 2,500 pound shells just under 13 miles. That, however, isn’t far enough to cross the English Channel so the 18-inch gun was replaced with a longer range 13.5-inch version that could hit targets in occupied France during World War II.

Caliber: 460-millimeter
Origin: Empire of Japan
Though it was illegal under international law, the Japanese Empire went ahead with construction of two Yamato class battleships, each armed with nine Type 94 18.1-inch guns—the largest ever mounted on a warship. The guns had a maximum range of 26.1 miles (couldn't quite get that marathon) and fired shells weighing around 3,000 pounds. To avoid getting caught the Japanese claimed the Type 94 was much smaller than it actually was.

Caliber: 520-millimeter
Origin: Scotland
Though its shell weight can’t rival more modern weapons, Mons Meg’s massive 520-millimeter caliber and incredible useful life of over 200 years are nevertheless very impressive. The medieval bombard was built in 1449 and served until 1680 when its barrel burst. The gun’s huge stone cannonballs weigh around 400 pounds. Make your own stones jokes.

Caliber: 600-millimeter
Origin: Nazi Germany
This huge self-propelled siege mortar was also known as “Thor.” Its shells were an incredible two-feet in diameter and weighed 4,780 pounds. The Karl-Gerät needed a crane, heavy transport truck, and multiple tanks to carry its ammo. It saw combat on the Russian front during World War II, but was ultimately just too big and heavy to be practical.

Caliber: 800-millimeter
Origin: Nazi Germany
These two railway guns were so huge that they required two parallel sets of railroad tracks to support their weight, which also made them wildly impractical. They were designed to demolish the hardened fortifications of the French Maginot Line, but the German strategy of just going around the line proved much more effective. Still, the mighty railway guns remain the biggest ever constructed and were capable of hurling a 15,650 [Not a typo -Ed]] pound projectile nearly 29 miles.

Caliber: 890-millimeter
Origin: Russia
The largest bombard ever built, the Tsar Cannon was never actually used in combat, though it was fired at some point in its long life. The cannon was cast in 1586 and has occupied Moscow ever since. Instead of a cannonball, the Tsar Cannon would have fired around 1,800 pounds of grapeshot.

Caliber: 914-millimeter
Origin: United States
There’s nothing “little” about this mortar which was designed to destroy the huge fortifications the army planned to encounter during the expected invasion of Japan during World War II. But Little David’s limited range (six miles) and questionable accuracy cast its potential effectiveness into doubt. Thankfully, the invasion never happened and the gun never saw combat. The mortar’s massive three-foot diameter shells each weighed 3,650 pounds.

Caliber: 914-millimeter
Origin: United Kingdom
Much like Little David, with which it shares the world’s largest caliber, Mallet’s Mortar never saw combat. Two examples of the 43-ton mortar were built in 1857 and were extensively tested. The gun could fire a shell with a maximum weight of 2,940 pounds or a lighter 2,400 pound shot. The 80 pounds of gunpowder used could fling the smaller round about a mile and a half.

Caliber: 280-millimeter
Origin: United States
Though its caliber is hardly impressive compared with the rest of this list, the M65 “Atomic Annie” is many times more powerful than all the other guns combined. The gun’s secret was a shell with a 15-kiloton nuclear warhead that punched way above its weight. Thankfully, the M65 was fired only once for a nuclear test known as “Grable” in Nevada (pictured). Maximum range was only 20 miles, which was cutting it a bit close when you’re firing off a nuke.

David Burbach rides motorcycles for a living and is a fan of all things that go boom. Find is lame-o tweeting @welivefreephoto.

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