I’ve just watched an old murder mystery, where the victim seemed to have been shot, but there was no bullet found in the body. I guessed the bullet was made of water ice. I was almost right, it was made of frozen blood.
A quick Google search tells me this is impossible; neither frozen water or frozen blood would make a lethal bullet. They would melt during flight, or fragment on impact, or not penetrate the skin, or whatever. It was on Mythbusters, apparently.
But are there *any *frozen substances that *would *make a practical bullet, which would then melt or evaporate due to body heat, or else dissolve in the blood?
What about a bullet made of frozen mercury? Would it be possible to kill someone with such a thing?
No, I don’t need answer fast. I’m not planning on killing anyone, and I don’t have the facilities to freeze mercury. Just scientific curiosity. It’s not even “for a detective novel I’m writing, honest”, nor does my friend want to know.
The Mythbusters could have done a lot more testing. They didn’t download the charge (I think) for reduced velocity. Did they try a sabot to prevent friction in the barrel? They didn’t put a simple copper cup on the base of the bullet (standard practice for soft bullets at high velocities).
Mercury might work but it would give the clue the person had been shot (as with the Pycrete).
There’s a Raold Dahl story (that was made into an Alfred Hitchcock Presents episode) where a wife killed her husband by whapping him in the head with a frozen leg of lamb, which she then cooked up and served to the police when they came. No murder weapon in evidence!
The massive Black Lizard Book of Locked-Room Mysteries has three separate stories with an ice bullet of some sort, one of them frozen CO[sub]2[/sub]. None of them use a regular gun to fire it as a regular bullet. So Mythbusters maybe should have read a bit more to decide what they were debunking.
I’d think the bigger problem with an ice bullet would not be its fragility, but its density. Water ice is an order of magnitude less dense than lead. I suppose you could compensate somewhat with a longer bullet, but then you’d probably have issues with tumbling.
Alfred Bester has a villain kill an old man with a bullet made of water in a gelatin capsule, in The Demolished Man. He knows it has no range or penetration so he shoots him in the back of the mouth.
Such a capsule would not leave an obvious wound - just from the back of the mouth (soft tissue which will close around the hole) into the medulla (“brain stem”). It would not penetrate the skull, so no exit wound.
And it would take an autopsy of extreme care and detail to find the 2" path of the “bullet”. Stick a pencil into the back of your mouth - now imagine a hole about 1/8" in diameter in that spot. How obvious would said hole be?
My problem with those old stories (most of which I’ve read) is the fact, already covered, that you’d still have an entry wound.
That’s why I appreciate the further thinking that led to the “back of mouth” idea.
I wanted to add another twist: a vintage Batman comic that had the murder weapon an “ornamental” crossbow in the victim’s study… with an ice cube keeping the trigger from firing. No evidence of why it fired, except a damp spot (noticed only by the Dark Knight Detective).
I thought it was just to eliminate bore markings, so there can never be a match with the gun. The police know it’s murder…but can’t prove it was my gun that fired the shot.
For murder without traces, I’m fond of the “household accident” method.
(Ah…that’s in the abstract, of course. Like reading mystery novels. No practical application whatever.)
Most bullets are mace of “frozen lead” – but lead has a much higher freezing point than Mercury, so lead doesn’t melt at room temperature. Freezing point and melting point are the same value. Mercury -39 °C, lead 327 °C
Cody’s Lab did a frozen mercury bullet (he built a custom cannon/gun for it with large thermal mass and cooled the gun so the bullet wouldn’t melt before firing):
