Indistinguishable guns

[rancke]

I was reading a mystery involving two matched guns (owned by two different gun collectors) that looks just the same but can, of course, be matched to whichever bullets was fired from which gun. And it made me wonder: In the Far Future, are there maybe manufacturing methods that would allow guns to be completely indistinguishable -- even down to the marks they leave on bullets? I'm thinking primarily about some sort of 3D printer, but maybe there are other methods too.

I can see two different ways this would work: Firstly, a process that inherently produced 100% identical copies, and secondly, deliberately scanning a gun and producing another one that was meant to produce identical scratches on bullets (for some nefarious purpose, of course).

In the first case, I imagine that wear and tear would differentiate different copies in time so that after a while they would no longer produce identical scratches.

Can anyone think of other possibilities and ramifications?

This is just idle speculation, but I can't help wondering if there isn't an adventure or at least a plot twist buried somewhere in the notion. Maybe a murder mystery where the players get thrown for a loop because they CAN'T be sure the bullet really was fired from the gun. Or maybe they KNOW the bullet wasn't fired from the gun, no matter what the evidence says, because it was owned by one of the PCs.


Hans

 

[far-trader]

A good adventure idea for sure. Perhaps even possible today, more easily so in the far future. However there are limitations to today's simple striation forensics that I would think would be overcome with advances.

What I mean is there's more to it than the individual gun's barrel at time of manufacture. You're correct that the wear and other changes over the use lifetime would change the two originally identical guns.

Copying a used gun introduces it's own complications but might work. I'm just not sure the idea is one that would fool the forensics techniques of the same era.

A high tech copy could be made that would fool a low tech investigation. But I don't think a high tech copy would fool an equally high tech investigation. So that's where I'd build the adventure. A high tech enemy sets up the mark to take the fall on a low tech world where the duplication will fool the local forensics.

Now that I think of it I vaguely recall a mystery built on the premise of two identical guns. Columbo maybe. Or I could be confusing the recall

 

[stealth]

How about a self-tempering barrel on a smooth-bore firearm? When the SR-71hits Mach-3, it's skin re-forges, giving it a very long-lived air-frame. The same could be done with a high-tech gun barrel, provided it had no rifling.

Also, aren't gauss guns smooth-bore? Spin is provided by magnetic bias, so if you wan't an untracable round, it's gauss.

And what about memory metal? Fire it once, the heat causes the barrel to revert to original rifling. Sure, the police know it was your gun, but too bad, they can't prove it was you.

 

[veltyen]

This is just idle speculation, but I can't help wondering if there isn't an adventure or at least a plot twist buried somewhere in the notion. Maybe a murder mystery where the players get thrown for a loop because they CAN'T be sure the bullet really was fired from the gun. Or maybe they KNOW the bullet wasn't fired from the gun, no matter what the evidence says, because it was owned by one of the PCs.Hans

One of the problems with forensics based TV, is that TV writers very seldom know any solid forensics.

It is true, that in some cases, bullet markings can be used to limit the likelyhood of a bullet being fired from a weapon. But much like the other forensic techniques that are represented as "100% foolproof!" like DNA matching, fingerprint matching, polygraph tests and so on, the actual forensic usefulness is highly variable from case to case.

Often there isn't enough to go on because of fragmentation, for example. Often the composition of the fragments can be used to determine a "batch[1]" that the bullets may have come from. Which does open the interesting possibility of filching bullets from the PC's for a murder and then using the same type of gun.


[1] Batch could be a particular manufacturer, and not a lot more however.

 

[Andrew Boulton]

And then there's lasers...

 

[Starviking]

And then there's lasers...

Gauss guns and shotguns too...

 

[rancke]

The point wasn't to have no useful clues at all. The point was to have potentially misleading clues.


Hans

 

[Rover]

It is not just the barrel that can leave a trace. The firing pin, chamber and ejection mechanism can leave marking on ejected casings. So a shotgun has no rifeling, but the shells can be matched.

Also people who wipedown a gun for finger prints may not realize that fingerprints can remain on bullets in the magazine and or the bullets themselves.

R

 

[stealth]

Memory metal.

The point wasn't to have no useful clues at all. The point was to have potentially misleading clues.

Make a gun out of memory metal. Then get your patsy's gun and dupe its rifling and pin by reforging. After you use it, the memory metal should revert to your original forge, due the frictional heat caused by your deadly bullet.

Of course, if you get caught with a memory metal gun, you need a good lawyer and an antique dealers license. Sure, you might still go to jail, but it won't be for murder. And you could still skate.