Why no firearms?

Question

In this world, magic exists. The technological level is medieval, but weapons like magically reloading crossbows exist. Magic has the following rules:

1. All magic requires runes and a verbal activation (saying 'magic words' that correspond to the runes). Runes are one-use only.
2. Any spell lasts a maximum of one minute (no enchanting)
3. Any spell has a certain maximum amount of power, and will not complete tasks under that power (you can create a small fireball, but can't make a storm or teleport)
4. Any spell takes three seconds to take effect after the verbal component has been said (gives time for a counter-spell)
5. Runes can be traced on a surface (traced rune) and can then be activated only by the maker, or engraved/written (engraved rune) where they can be triggered by anyone holding the object.
6. All activation phrases must be yelled, and cannot be muffled (can't use magic while gagged or holding cloth over face)

So the question is: Why have the humanoid denizens of this world not developed magical firearms?

Answer 1

Because medieval metallurgy stinks. While decent steel was available, it was extremely expensive. Decent, relatively inexpensive steel only appears in Europe around the late 1500 to early 1600s which is well into the Renaissance era.

One of the oft overlooked aspects of making a firearm, or almost any tool and weapon, is metallurgy. Making a chamber able to withstand the enormous pressures of an explosion in a very small space, plus the barrel to withstand all those hot gases, is remarkably difficult.

Black powder is relatively low pressure compared to smokeless powder, and the pressure wave was relatively slow. This required a long barrel to get the most velocity out of it. The low pressure meant your firing chamber could be relatively weak compared to what is needed with smokeless powder. So late medieval metallurgy was able to deal with black powder muskets and cannon.

Firearms, really hand cannons, first appear in China around the 13th century and show up in Europe and Arabian hands in the 14th. Around mid 15th century, the arquebus shows up, the first thing you'd recognize as a musket. This places only the most basic hand-held firearms solidly in the late medieval period. That's what your society would be capable of.

Regardless of whether it's black powder or a tiny magical fireball, it's the same pressure for the chamber to withstand. And it's the same lead ball going down the same inaccurate smooth barrel. So they'll have the same limitations. Nobody's going to have a Glock, magic or no magic, with medieval metallurgy. You get the equivalent of an early black powder musket, at best.

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That said, there are reasons why you'd make a magical musket. Most of the innovations in muskets were to speed loading, and make the trigger more reliable. Magic can help.

1. No powder to carry around and keep dry, just carry the shot.
2. No powder residue to foul the inside of the chamber and barrel, a serious problem with black powder.
3. Loading would be a bit faster, no powder to pour and pack in.
4. No trigger mechanism to reset.
5. No expensive and unreliable springs.
6. No lit match. No flint to keep spaced just right. No touch hole.

Not having to deal with powder nor a trigger mechanism would be of great importance to a late medieval musketeer. Powder has to be carried, measured, and kept dry. Powder residue quickly builds up in the barrel and chamber requiring cleaning. The black powder residue could build up so fast in the barrel you'd literally have to use smaller balls if you didn't get a break to clean your gun in battle.

Trigger mechanisms will be the bane of firearms until percussion caps in the 19th century. The first would be a matchlock, literally carrying a slow burning rope to touch off the gunpowder. Then wheellock, using a spring to turn a wheel against a flint to throw sparks onto the gunpowder... hopefully. But wheellocks were very expensive, springs are expensive with medieval metallurgy. Finally the flintlock, a piece of flint striking steel, became the norm in the mid 17th century, but the matchlock stuck around.

It's not until the mid 1800s that we finally get the cheap, reliable percussion cap primers that we know of today: a small explosive that reliably detonates with a very hard whack.

If you told a medieval musketeer they could have a musket which required no powder, no match, no flint, and no trigger, they'd jump at it.

Answer 2

Because 4.

That's so much time compared to a bow, it's not feasible. A magic wand unleashing the wrath of gods and killing half an army (or at least a few guys), sure, but a magic 9mm projectile that goes off three seconds after shouting hey you there watch out 3 ... 2 ... 1 ... heck, I'm pretty sure even I'd have a good chance of dodging that after a little timing training. Plus it gives so much time to just pull my bow and shoot that guy pointing his gun at me ...

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For big battles those disadvantages might be small compared to having easy to use weapons with good range and penetration, however the reason muskets were invented before rocket launchers is physics. Magic has other boundaries. Something way more destructive is possible. Why fire only one bullet if you can fit 100 into a box, aim at the general direction of the enemy forces and magically release all off them at once?

Depending on the exact specification of the magic there is always a way to design a more powerful weapon, unless all the magic can do is imitate a little explosion like used in a musket.

Answer 3

Because nobody had a reason to invent them.

When searching for more and more effective ways to kill someone at a distance we (in our non-magical state) found that certain combinations of barrel, gunpowder and slug could be very lethal where mechanical weapons had pretty much reached the limits of their effectiveness. But the development of the firearms took a lot of time, metallurgical skill (as Schwern's excellent answer pointed out) and a concerted effort on the behalf of those people who wanted to kill other people at range better.

Now consider your system. Why would you possibly want to invest time, energy and money into creating a tube that fires an inaccurate ball of lead an indeterminate distance when you can instead slap a rune of target finding onto your arrow? Why waste effort creating a weapon that needs a three seconds to fire when instead you can have a three second magical reload and be confident of actually shooting your target? Why bother making a gun that can pierce armoured foes when instead you can buy, ready made and compatible with your favourite crossbow, a Bolt of Burrowing (now with 110% more agony)?

Depending upon how long magical effects can last and what you're allowing in your magical system you can even pre-activate certain runes to avoid the lead time on the spell and the chance of a counter. If I nock an arrow with a pre-carved 'explode on contact' rune (naturally being careful not to let the tip of the arrows touch anything once armed) then I effectively become the magical equivalent of a mortar. A full group of archers with such weapons could be far more effective at area denial than even the best group of magi-musketeers. Naturally the effectiveness of such an approach is limited by how long magical effects like this last once activated, but as long as arm to fire time is shorter than the magical dissipation time (or a person holding a weapon can re-activate runes as much as they like), an archer with a pre-nocked arrow can be far more effective than a gunman with the flint ready to fire.

Not only that, but if you consider the difference in size between a lead ball and an arrow shaft you have much more room to be inventive with. A medieval war arrow has plenty of shaft on which to write destructive or guiding runes. A lead ball? Not so much.

Basically what I'm saying is that in your world there is far more incentive to use magic inventively to make existing ranged weapons more deadly than there is to invent a whole new system of weaponry. The limits of effectiveness for the humble crossbow are the limits of your magic system itself, so nobody actually needs to try make a better ranged weapon (except by trying more and more potent magics). Those who do try to make magical firearms quickly find there is more damage to be done (and hence profit to be made) from carefully crafted weapon runes.

Answer 4

I have wrestled with this specific problem myself (as is likely a common theme for this category). I am still working on the story, so I won't divulge too much of my solution, but here is the basic idea to use as a working example.

The world upon which the story takes place is unique. It exists in a null space of sorts leftover from an ancient race with the power to create and destroy worlds, stars, etc. The 'null space' is a bit like an old and forgotten janitor's closet, but an entity from that era yet remains in the form of a 'dark star' which is thought to be a sentry of sorts for the strange discontinuity in space. It is purported by some to be the cause for the incomprehensble source for the failure of most sorts of complex technology on the planet's surface. While many sorts of simple technology is unhindered, most more complicated items (such as guns) simply will not work. One theory goes as far to claim the strange opaque stellar phenomenon is able to alter reality, effectively changing the rules of physics and chemistry within the dominion of the null region. Evidence of technological failures may be found in the excavated remains of interstellar vehicles which helplessly fell victim to the planet's gravity well after losing all propulsion and systems upon approaching the lone planet....

Of course, the reason for the need of such a thing is to magnify the use and importance of Rhunic incantation, or magic.