# Could a pearl make a good bullet?

If I were to use a pearl instead of a bullet in an old fashioned flint-lock pistol or a musket, could it survive? What would it do on impact? Would it be too light for an effective ammunition?

Basically, what would be its properties as ammunition?

EDIT: I did not consider the world to be a major concern, since it has nothing to do with the question.

My world is in the early stages of discovering the "New world". People made a special boat in an attempt to discover a new continent, but they found countless numbers of small islands forming a large crescent formation at the bottom of this formation is a island that is full of pearls. I wondered if I could have the people from southern islands carry a round pearl with them as a reminder of their homeland and for good luck and to remind them that they should not be controlled by greed and as an emergency ammo.

So I wanted to know if it would be possible to use a pearl as ammunition. Because shooting that pearl would be a sign that you are not controlled by greed and many wear the damaged pearls as a proof. But I don't know if the pearl would survive the impact.

Southeners consider the explorers as invaders. They have more developed firearms than the people from the continent, so they consider guns as standard weapons, while the continent knows only about ship cannons. On the islands there are temples made from rare materials, that form a prison for a demon of greed. If they get torn down it will be released. (that is the only magic in this story.)

As you can see the world has nothing to add to my question.

• While the physics of pearls as ballistic weapons is interesting, I feel that your question really has, well, zero worldbuilding interest. Please take a look at the Help Center and rework your question so that we get a sense for how this material will make for a good bullet in its geopoetical context. – elemtilas Mar 25 '18 at 0:57
• @elemtilas In the help center what topics can be asked the following criterion is given about questions that can be asked : "How to achieve a specified effect in a defined world, including by the use of biology, technology or magic, while maintaining in-universe consistency" This question is about achieving a specified effect, namely, using pearls as bullets. This makes it on-topic. – a4android Mar 25 '18 at 3:17
• I don't know about a pearl, but I'm pretty sure perl has killed people. – Pharap Mar 25 '18 at 3:18
• Where's the involvement of this situation in a fictional world? What story does it help you to tell? This isn't a world holding question, it's a random what if... – Nij Mar 25 '18 at 3:47
• @a4android No non-Earth world is actually defined. The OP doesn't ask for a "specified effect" (just a generic would be "good") nor asks anything about in-universe consistency. Surely, asking if a pearl makes for a good bullet is on topic for Physics-SE or Ballistics (if there is one), but not Worldbuilding. That is why I asked the OP for some worldbuilding context! – elemtilas Mar 25 '18 at 4:10

From the mid-18th century, however, British forces used just 3 main uniform sizes: Musket, c.31g ball; carbine, c.23g ball and pistol, c.13g ball. (source)

You'd need a pearl the equivalent size to a 13g lead ball for a standard flint-lock pistol. However, lead has a specific density of around 4-5 time that of pearl (~11 vs ~ 2-3), so a pearl of that weight would be too large for the pistol, while one of the right size (for the calibre of weapon) would - I assume - be too light to deliver the same impact.

Pearls themselves are fairly tough, so propelled at sufficient velocity would be damaging. You might just need a custom weapon to do so.

The biggest problem of, course, would be finding sufficient pearls to use as ammunition, and addressing the question of why you wouldn't exchange each pearl for a wagon-load of lead-shot ammunition for your flint-lock musket or pistol?

EDIT: Expanding on this a little, in a constructed world it might be that pearls are more readily available, and/or deliberately harvested (and marketed by a particular culture or population. @ohwilleke (in comments) suggested particular vulnerability akin to werewolves and silver bullets - if this existed it could create a market for 'pearl bullets'.

Taking this further, if pearls are somewhat toxic to a particular target - and given that small pearls will be more common than large pearls, perhaps they could be used as 'shot' (i.e. multiple small projectiles per discharge) rather than as a straight replacement for musket balls - this would increase the likelihood of hitting the vulnerable target (given that pre-rifling, accuracy was poor), which might be important if its something as dangerous as a werewolf. While I've not been able to find any reference to use of shot in flintlock muskets or pistols, there is a passing reference to this for the arquebus, so it has some plausibility:

It was sometimes advocated that an arquebusier should load his weapon with multiple bullets or small shot at close ranges rather than a single ball.[ wikipedia, citing "Barwick, Humfrey (1594). A Breefe Discourse"]

• I would imagine that pearls might be the equivalent of silver bullets for werewolves in some world, with toxicity towards some specific kind of foe. It could also be used as secondary ammunition to the killing ammunition for the purpose of leaving a trademark identifier of the perpetrator to send a message to people who might cross you in the future (a bit like Russians using Polenium (sp?) when they could kill much less elaborately. – ohwilleke Mar 25 '18 at 5:35
• @ohwilleke: Polonium. en.wikipedia.org/wiki/Polonium – Peter Cordes Mar 25 '18 at 7:44
• The rarity of pearls is not a point of this question, but I asked without context, so thank you. You can leave it there, I like it. I also appreciate the "special ammunition" I think that is a wonderful idea. How badly damaged would the pearl be? Will at least half of it survive?(if it hits a human skull or a side of something like a wolf) – Nuloen The Seeker Mar 25 '18 at 9:29
• Using it as shot would also avoid the problem of bore. Pearls come in different sizes and very few would fit a given weapon. – Paul Johnson Mar 25 '18 at 9:51
• @ Nuloen. This is just speculation, but I would imagine that the pearl(s) would be damaged by impact, and may even fragment if propelled with sufficient velocity. Of course, in a fictional world, you could change the material properties to make them tougher, if you need survivability. – Nick Mar 26 '18 at 8:44

Assuming it is a round enough pearl, it will work as a bullet: it is strong enough to survive firing from a smooth bore firearm. Minor chipping will not affect the aerodynamics much, just compare it to ball type musket ammunition for accuracy.

It will not have much stopping power however (1/5th to 1/6th the density of a lead bullet, which means about 1/10th the kinetic energy). It has slightly more mass than a rubber bullet of the same size so using lethal range for a rubber bullet might be a good shorthand, if you can find it for a musket. Pearl buttons have been used as impromptu ammunition in pistols and did penetrate at point blank range so you can get penetration. Keep in mind even a blank cartridge can be lethal from a short enough distance (within a few feet) so a pearl can definitely be lethal.

• Why do you say 1/5 the density leads to 1/10 the kinetic energy? – frodoskywalker Mar 24 '18 at 23:56
• I like your post, but I find this part: Pearl buttons have been used as impromptu ammunition in pistols (...) hard to believe without a citation. – Renan Mar 25 '18 at 0:11
• There is a magician trick called the bullet catch in which a blank load is fired from a pistol and the magician fakes catching a hidden bullet. the trick is exceptionally dangerous however as the audience member could slip anything down the barrel and creating a lethal projectile. known examples include nails, coins, and buttons. At the time the trick was popular buttons were mostly made from pearl (bivalve shells) – John Mar 25 '18 at 17:07