Falsify ballistic test results by...

Hypothetically. Is it possible to alter a bullet by scuffing or scoring it by some means, THEN produce the loaded cartridge and fire it. Then fire a fresh load from the same weapon and have a ballistics expert compare the projectiles only to come up with a false, “no match” result?

Also, in the annals of crime. has a criminal ever attempted this?

Just wanted to add:

I should have phrased it as, “How likely would it be that such a technique would fool a ballistics expert?”

I remember stuff like this from a Perry Mason book, maybe other stories as well. In real life, don’t know. Wouldn’t an intelligent criminal toss the gun in the river instead of keeping it around for the cops to test?

Indeed they would. And if we are going to get picky about it, they would also use a revolver so the police would have no shell casings to analyze. But that’s not the question.

Well it sort of is. The criminal isn’t being too intelligent if this is the first thing way he thinks of to cover up his crime. In that case he probably doesn’t know what he’s doing and wouldn’t fool the ballistics expert. But I suppose someone who knew enough about ballistics testing might be able to fool them and would choose this method. So that kind of answers the question. It’s not that likely considering the limited number of people who have enough to knowledge to fool the experts, and the limited number of people smart enough to try and cover up their crime with pre-planning, but dumb enough not to do it right. And whether it would fool them is based on which group you’re in.

This is far outside of my expertise, but I would be very surprised if it worked. The barrel of the weapon is going to leave marks on top of whatever marks were put there in advance, and those marks are going to line up perfectly on a ballistics test. I would imagine that a forensic examiner would recognize the weird additional scoring done to the bullet.

I’m also wondering if the marks put onto the bullet before firing would look different, since they might trap powder residue instead of beings scraped clean by the barrel as the marks made during firing would.

Wouldn’t work. The barrel would mark the bullet over the scorings, making them meaningless. What you need to do, if for some reason you have to keep the gun, is after firing the “to be tested” round, mar the barrel with something. Scratch it up good. Then go to the range and put 500 rounds through it. By that time the test bullet and one fired from the pistol when the police check will have virtually no points of comparison.

No one ever fires bullets made of ice. The fools!

I seem to recall reading about a guy who actually did this. By firing hundreds of rounds, he wore the barrel enough that new rounds no longer matched those from the crime. He was implicated by other evidence, and because he did this in his rural back yard, bullets collected there bridged the gap. I can’t recall if this was real or fictional though.

That’s why you shoot at a public range. One with a hard metal backing plate behind the targets.

If a bullet actually enters a body, doesn’t it mushroom? Ballistics are only useful if you miss and shoot into a wall. <- Speculation

Don’t miss!

Most guns jam when loaded with frozen turkey legs.

Completely wrong. If the bullet fragments, it may be difficult, but even a distorted bullet may have enough striation for a match. The steel plate of a gun range may flatten the bullet enough to destroy all detail, but a human body, not so much.

Si

It mushrooms, but the “stem” of the shroom will have unique markings.
See here:
Imgur

ETA, a much cheaper and easier alternative to shooting 500 rounds through your barrel is to simply order a replacement barrel for the pistol. Use the new barrel for the crime, then put your old barrel back in the weapon and dispose of the one used in the crime. Many firearms have serial numbers on the barrels as well. So by placing the original barrel back in the weapon, all the serial numbers will match and there will be no suspicsions.

If I’m ever involved in a shooting, I’ll just make the ballistics expert my second victim.

Better make him the first, in case he’s really good.

Wouldn’t they have a record of purchase that connects you to the replacement barrel if it is found, though?

Wouldn’t that double the amount of evidence (bullets) that could be used against you?

Can I assume that you chose the term “most” because you haven’t finished testing them all yet?

For a barrel? No.

If you’re super-paranoid (or super careful), go to a gun store out of town and pay cash.