(To specify, it doesn't have to be specifically a crossbow, if you can think of another weapon that can fulfill the same job like a speargun or a harpoon, or even just a regular bow you're welcome to suggest them as well)

So, long story short, ice bullets are too lightweight to function, as various answers on this site and others have explained. But what about a bolt sculpted from ice? (or a spear or harpoon, see above)

Would a bolt sculpted from ice and fired from a modern crossbow be enough to kill a person?

Let's assume it's a highly trained assassin firing the weapon, so they can hit vulnerable parts of the body like the throat or jugular if need be.

EDIT 2: It just occurred to me that not everyone might be clear on why I'm looking for Ice-based Weaponry. It's the same reason behind the need for Ice Bullets. The reason is that these arrows will (theoretically) dissolve in the body of the target, leaving no way to determine that they were shot. I'm really sorry I didn't notice this earlier, although it looks like I caught it early enough that no one gave any answers that didn't answer my question.

Edited title because I didn't want people thinking the crossbow itself was made of ice

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    $\begingroup$ A crossbow quarrel made of ice will also be very lighweight and prone to shattering into pieces instead of penetrating the target... $\endgroup$
    – AlexP
    Commented Apr 19, 2018 at 2:22
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    $\begingroup$ Arows have to flex to function so they are just impossible from ice, not sure about bolts . $\endgroup$
    – John
    Commented Apr 19, 2018 at 4:20
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    $\begingroup$ One practical problem is that the arrow heads could stay frozen together especially if they experience changes in temperature. There are plenty of issues ragarding the storage of these ammo. $\endgroup$
    – Vincent
    Commented Apr 19, 2018 at 5:05
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    $\begingroup$ I replaced "arrow" with "bolt", because crossbows fire bolts, not arrows. You can revert if you so desire. $\endgroup$
    – RonJohn
    Commented Apr 19, 2018 at 5:23
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    $\begingroup$ A small part of me wants to offer a bounty on this question, requiring a "hard-science" answer referring to young's modulus of ice versus the woods, metals, and composites of typical bolts and arrows, compared to the mass of the bolt or arrow, against the forces and acceleration produced during firing of a bow, and maybe even the deceleration when impacting human skin. Maybe we can get an ultimate canonical answer to whole ice-projectile trope. $\endgroup$
    – cobaltduck
    Commented Apr 19, 2018 at 11:34

5 Answers 5


Ice is really too brittle to make weapons from easily but by adding wood pulp you can make pykrete which produces a stronger end product.

If it should melt, you're left with mushy paper

Pykcrete can be used to make knives and other pointed weapons capable of stabbing someone without shattering.

It won't hold together like metal but will hold together enough to get the job done.

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    $\begingroup$ Finding some mushy paper inside someone is nice and subtle, definitely more so than a normal wooden arrow. Great answer, and I think it's about as close as we're going to get to true ice ammunition. $\endgroup$ Commented Apr 19, 2018 at 4:41

Making bolts or arrows out of ice is not a good idea, the arrows could break under the strength of the crossbow, because the force has to come from the back of the projectile to the tip, that produces vibrations and bending. The long thin shape of an arrow is not optimal for these reasons, and it is the projectile that modern crossbows use. Arrows also need fletching, that you can not make from ice, because it needs to be flexible at least a bit. The smaller thicker bolt could work, but the kill would still not be guaranteed, since it could break easily if it hits bone, because you have fairly thin point made from a very brittle material. You could compensate for the vibrations with a tube, or go full Slingshot channel and use pressurized gas to propel the projectile.

BUT have no fear, for I have found a different solution, that still uses ice projectiles and crossbows. But they are nolonger sharp and pointy.

The answer to this problem is quite simple. Shoot hailstones instead of icycles. You get lots of ice bullets and this type of crossbow. Round projectiles are ideal even for a brittle material like ice.

Hailstones have good aerodynamics (all round things have), they are heavy, they withstand the shooting as well as the impact.(as proven many times in nature) In nature they still do some harm, but if you use a crossbow, you can propel them far past their terminal velocity. This projectile also doesn't lose its functionality if it's in a warm environment, yes it will melt eventually, but while it still has enough weight it will work just fine, while the arrows and bolts will become dull.

But even this projectile can be very light compared to the intended ammunition (lead), so unless you have a very powerful crossbow, don't expect good range or accuracy.

If you want to make the bullets somewhat pointy, you could use a tear shape, like on sling bullets.

  • $\begingroup$ You could also go for a sling directly, but those require more training than crossbows. $\endgroup$
    – Eth
    Commented Apr 20, 2018 at 14:51
  • $\begingroup$ @Eth Slings require lots of space and are not as accurate and do not have a consistent shooting power. They are also considerably weaker than a modern crossbow, both in power and range. They also require time to throw the projectile, while an assassin can come with a crossbow already ready and then executes its target in one pull of a trigger and dissapears again. And a man flailing something around is more conspicuous, unless you are in The land down under. Slingshots have some of the weaknesses as well. So I don't think they are the best solution. $\endgroup$ Commented Apr 20, 2018 at 16:49
  • $\begingroup$ On the other hand, slings are easier to conceal, and can be more silent. A trained sling user can also launch the stone at the first move, without letting it circle first - in fact, some guides I found online recommend this approach. And they are still deadly enough against an unarmoured opponent, the Antiquity and High Middle-age had slinger troops alongside bowmen. Not good for all cases, but can be an interesting option. $\endgroup$
    – Eth
    Commented Apr 23, 2018 at 14:05
  • $\begingroup$ From my calculations ice ball about the shape of a pingpong ball (d=0.04m) would weight cca 1.2oz. from what I found on forums 3-5oz is suggested as "effective". But my knowledge on slings is lacking. I think that a big heavy ball thrown by sling would have too much impact surface while a small projectile wouldn't have enough weight to be lethal. Mercury or maybe gallium could do just fine. The projectiles would still melt and could poison the bloodstream, but they are detectable and OP didn't want that. So I think that under these conditions the crossbow is a better option. $\endgroup$ Commented Apr 23, 2018 at 16:20
  • $\begingroup$ The sling has potential to throw sharpened objects that could be more efficient, but I don't know about the range vs. accuracy. $\endgroup$ Commented Apr 23, 2018 at 16:22

Falling icicles can and do kill people. (With greater regularity than I thought, based on multiple news sites I found online, like this one from Chicago https://www.citylab.com/environment/2012/02/chicagoans-vs-falling-icicles-history/1219/ ).

So, yes, projectile ice can kill people. The question is one of firing speed and weight. Can you fire the crossbow from height? The acceleration by gravity would help. Also, most of the killers are in the 5 to 2-to-4 kg range. A typical wood arrow is around 18 g according to Wikipedia. That’s going to take a pretty massive crossbow.

So I think the answer is likely “no.”


Go back to Pre-History....

The Atl-Atl

From long long ago, many cultures across the world used a variety of spear throwers in warfare all the way up to Aztecs battling Spaniards. The concept is simple. Use something to add length your trowing arm and launch a projectile. The concept is even out there today in those ball throwing things you can buy for your dog.

The Meso-American version was basically a stick with a cup or hook on one end, a handle at the other. They loaded it with a spear or a dart. With and overhand throwing motion the dart was propelled forward and the mechanical advantage provided by the launcher made the projectile fly farther and faster. It couldn't affect Spanish plate armor, but it was hell on mail and cloth armors.

How would this work for you? You could go in a couple of ways. One of them is to create a spear about 2 or 3 feet long. I'm reasonably certain that a 3 cm shaft around 60 or 70 cm long and only sharpened along the last 3 cm or so would hold together and have enough mass to be lethal over 30 meters or so.

If your test of the ice spear doesn't work out, freeze spheres of water and get into the sport of Jai Alai. That game has a thrower that operates on very much the same theory as and AtlAtl. The ball moves at speeds approaching 290 KpH! A 5cm radius sphere will weigh about 1 kg (check my math, it's been a long time since geometry). So if kinetic energy is 1/2 * mass * velocity squared, that means a 1 kilogram ice ball moving that fast is going to have 3200 Joules. The energy from a .45 ACP bullet is around 477 Joules. That should easily be enough to shatter a skull at Jai Ali speeds easily. It's very likely that the Ice ball will also shatter upon impact, meaning less time for the bits to melt away.


I have read a fiction book where murder created bullet from ice covered by chocolate coating. Then he armed pistol with this bullet and killed shooting to the open mouth. The main idea was that there was no bullet left which made investigation hard.

This murder was made at point-blank range and brain damaged directly. So if you want ranged weapon you need happy shot and great sniper. Since you want crossbow which is less powerful than gun, you need a good luck also.

But I suppose it's possible. The idea of such kill is to put damage similar to punch, like boxer could kill with single (un)happy knock. Ice bolt even doesn't need to penetrate the skin. Crossbow is more powerful than boxing punch so all you need is to have projectile durable enough to not break while hitting (or most of energy would be wasted to shatter instead). It's possible with some cover: clay, paper or something else what would be supposed as a trash at the place of kill.

Ice bolt is relatively light and would lost energy very fast. That's why I suppose such shot should be done at a close range (less than dozen meters). Also no armor on a prey and target only to the head. And lot of luck.

The story was The demolished man by Alfred Bester.

  • $\begingroup$ Do you have a non-fictional source for this claim? The OP noted that previous questions on this stack have concluded that ice bullets wouldn’t work. $\endgroup$
    – nick012000
    Commented Sep 28, 2019 at 5:36
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    $\begingroup$ Blank cartridges are potentially lethal when fired within few feet, the wound does not have to be penetrative, even only the paper wadding can cause a death by blunt trauma. en.wikipedia.org/wiki/Jon-Erik_Hexum#Death $\endgroup$ Commented Sep 28, 2019 at 11:09
  • $\begingroup$ @nick012000 My claim has two statements: 1. Crossbow is more powerful than punch even from professional boxer. 2.(un)Happy punh could kill and conclusion that shot from crossbow to a head could kill. Do you need sources for statement 1 or 2? $\endgroup$
    – ADS
    Commented Sep 29, 2019 at 8:16

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