what would allow for the use of cannons but not handheld guns

Question

I'm looking to create a low fantasy world set in roughly the equivalent of the dark ages such that cities are defended with castle walls and armies are equipped with swords, axes, spears, bows, crossbows, etc.

I would like one of the kingdoms in this world to be capable of quickly breaching enemy cities as such I thought I'd give them the sort of massive bombard cannons the Turkish once employed. However, I'm not interest in allowing any sort of rifles or pistols. So my question is what sort of constraints would allow for this kingdom to build and utilize these bombards without also allowing guns?

Answer 1

Why should there be any constraints needed? Napoleonic rifles were more than three centuries away from Turkish bombards. That should be plenty of time for your story to happen before the rifles arrive.

Edit (revised answer):

One way you could do it would be to have really lousy explosive powder available. So lousy that you need large quantities to fire a shot with any force, and too much to be practical for a person to carry or a hand-held gun to hold.

Answer 2

Your people lack strong metals. But they have gunpowder.

https://vassallohistory.wordpress.com/the-fougasses/

Native Americans had gold, copper and silver but no smelting technology - no bronze or iron. One might make a passable edged weapon out of copper if there was enough of it, although stone is a decent rival to copper as regards weaponry. The ability to make gunpowder is a whole separate branch of tech.

Your people use holes cut in the earth to make their bombards. These are called fougasses.

https://en.wikipedia.org/wiki/Fougasse_(weapon)

A fougasse /fuːˈɡɑːs/ is an improvised mortar constructed by making a hollow in the ground or rock and filling it with explosives (originally, black powder) and projectiles. The fougasse was used by Samuel Zimmermann at Augsburg[2] in the sixteenth century, referred to by Vauban in the seventeenth century, and well known to military engineers by the mid-eighteenth century. This technique was used in several European wars, the American Revolution, and the American Civil War. The term is still used to describe such devices.

You could make these and fire stone shot without having smelting tech.

There is not a good way to turn a hole in the ground into a handheld weapon. That I can think of right now. Still thinking.

Answer 3

Your people lack black powder. It was never invented. Instead, they use steam cannons.

Steam cannons have the [dis]advantage just right for your story: they really can't be made small, because of the whole steam thing. They have other disadvantages though - they are slow to fire, inconvenient and slow to reload, all the thing that I would say suit your story.

However... Cannons aren't as effective as you might think. Yeah, a big cannon can break down a wall, but so can a massive trebuchet. Siege warfare isn't as simple as it sounds. The debris remains in the way, and the terrain barriers still be there (be it a moat, or natural high ground). Cannon gives an advantage, but it doesn't mean your civilization will just completely stomp fortifications. What I'm trying to say is that you might want to read something about siege warfare for your story to feel more realistic.

Answer 4

Bad material science: If you can not produce high quality metals, you may need bigger metal parts to use the same high pressure in the barrel for a high-velocity small bullet, thus making hand-held guns to heavy.

Answer 5

There is no way you could prevent the invention of hand held cannons. It's logical to scale up or down a technology and especially in war. If you have the metal tech for the swords, you have it for guns.

There were several sorts of gunpowder for different applications and the stuff is readily experimented on as it's just ratios of ingredients basically. So poor quality isn't going to be the reason.

So one option might be social ones where there is a prohibition recognised by both sides that firearms are not allowed. This seems unlikely though.

Or, perhaps better for your question. Make one kingdom the only one who knows about gunpowder and it's a state secret. They don't arm their guys with handheld guns because they don't need to because they have such a huge advantage and they're holding them back as an awesome secret weapon if everything goes South on their route to World domination. Plus it's easier to capture one soldier with a gun and analyse the tech, than it is to capture a well protected cannon a mile away.

But make gunpowder a secret and the manufacture of cannons etc,. done elsewhere and just purchased. Perhaps even in terms of hiring a cannon brigade of mercenaries who have the esoteric weapons and the magical knowledge of how to use them.

Answer 6

https://en.wikipedia.org/wiki/Wooden_cannon

You need a gunpowder and a forest. Iron is not required, but something like a barrel rings can help.

These technologies are quite away from making a handgun.

Answer 7

It could be that the people in your story never discovered black powder gunpowder, but instead use Nitroglycerin or a similarly unstable chemical to cause the explosions in the cannon.

From Wikipedia:

In its pure form, nitroglycerin is a contact explosive, with physical shock causing it to explode.

Early in its history, liquid nitroglycerin was found to be "desensitized" by cooling it to about 5 to 10 °C (40 to 50 °F). At this temperature, nitroglycerin freezes, contracting upon solidification.

Pure nitroglycerin would be too dangerous to carry around in a hand-held weapon, and the only way they can use it would be to transport it with ice blocks, before carefully putting it in the cannon and thawing it.

They would also need only a small amount, since nitroglycerin is manyfolds more explosive than black powder.

The technology involved in desensitizing it(giving it stability) enough to be used in handguns is also quite complex.

The use of such an unstable explosive in the cannons would also introduce intricacies to the wars, making the transportation logistics interesting.

In April 1866, three crates of nitroglycerin were shipped to California for the Central Pacific Railroad, which planned to experiment with it as a blasting explosive to expedite the construction of the 1,659-foot-long (506 m) Summit Tunnel through the Sierra Nevada Mountains. One of the crates exploded, destroying a Wells Fargo company office in San Francisco and killing 15 people.

As can be seen from this paragraph, the transportation would be very risky, and I’m sure the cannoneer position would have to be considered a high-risk occupation if explosives similar to nitroglycerin were used.

Answer 8

Three important things.

1. Bad materials sciences. It is impossible to create fire-arms without steel. Period. If you try to make them from something else, they literally blow up in your face.

2. Extremely humid weather. If we are talking about a ~1400s level of technology, then they would not have any better ignition mechanism than the Serpentine Lock. The one bad thing about the Serpentine Lock, which eventually caused it to be phased out, is that it was unreliable in very humid weather.

3. Unstable munitions. Like @Enthus3d said, they would be unlikely to use small-arms if they only have Nitroglycerin. However, I do not suggest making this the reason, as it is extremely unlikely that they would be able to develop Nitroglycerin before Black Powder.

For further reference on this subject, I suggest looking at the David Weber's Empire of Man series.