What makes a mushroom?

[Ga9mm]

This may not be the appropriate place for this, so hopefully I won't get kicked out....

What makes a bullet mushroom? The real reason I ask is a long story, and I'm leaving out most of the details for a lot of reasons. I was at a party last week and a friend of mine had a .38 spl in his pocket. The gun went off, and the bullet went through his shoe, through his foot, and stopped without going through the bottom of his shoe. It came out intact, as if it were never fired.

I left out a lot because I don't want to get into the details. I know it was a stupid thing to do, and he REALLY knows that now. He's really young, and up until the firing pin hit the primer, he was pretty irresponsible.

I'm just curious why a bullet can go through a shoe, a foot, hit a bone, and come out without even changing shape a little bit. I don't know enough about ballistics and such for a .38, and am looking for some education.

Thanks.

[billwot]

I'm just curious why a bullet can go through a shoe, a foot, hit a bone, and come out without even changing shape a little bit. I don't know enough about ballistics and such for a .38, and am looking for some education.

Thanks.

There are a number of different factors that effect bullet expansion, but the major variable is the bullet type. In short, some are designed to mushroom, and some are designed to penetrate. Hollow-point bullets are designed to expand ("mushroom"), where solid bullets, particularly full metal jacket types, are designed to penetrate. There are many variations if bullet design, and their design strongly influences how they will respond when they enter different materials.

bill

[Ga9mm]

Thanks Bill. It was a solid, and I would have thought that it would have at least warped a little bit, especially since it hit a bone in his foot. Maybe I just need to read more about those, instead of only being somewhat educated on what I'm carrying... Mama always said there's a big world out there.

[corneliusiii]

I would be interested to hear more about it, like what kind of solid bullet. What kind of shoes was he wearing? I would have thought a solid bullet would have at least lodged itself in the floor. Inquring minds want to know! :)

[HootmonSccy]

Whewww.. By the title "What makes a mushroom?" I thought the answer was going to be "********"...

Hopefully for your self defense gun you are using hollow points and not FMJ's like this guy..
Hollow points mushroom which allows it to disperse ALL the energy of the round into the body it hits.. FMJ's can travel right through a body, only absorbing some of the energy, and hit WHATEVER is behind the intended target...

So, your friend is lucky that it hit his foot and didn't go off horizontally hit someone and the two people behind them.. Lesson well earned, and hopefully learned..

If you get a chance to talk with them some more, remind them that it is this type of incident that fuels people to take away our rights to carry and he should either smarten up, or not carry...

[Red Hat]

Other factors are velocity, caliber, bullet type, bullet weight, barrel length and muzzle energy. Since it was in his pocket and a 38 I imagine it was a 2" barrel. Firing a 38 cal non +P round FMJ round into a shoe and foot should only make a nice clean hole. Bone is not as hard as you think. Bones in the foot are small compared to other bones in the body. Once it went through the shoe most of the energy generated was lost. then the soft tissue slowed it down even more. He was lucky...it could have been a bigger round!

[Jim_Macklin]

The dynamic force that causes mushrooming is hydrodynamic pressure.
Shockwaves form on the bullet and are distributed uniformly into the bullet. Depending on the structural strength of the bullet material and to a lesser amount, the shape, the bullet expands to fill the wake of the shockwave.

In a dry solid, the bullet concertrates forces on the outside. If the force is high and the target softer, the bullet penetrates w/o expansion. If the target is hard/strong the bullet disintegrates.

[RugerP345]

So, your friend is lucky that it hit his foot and didn't go off horizontally hit someone and the two people behind them.. Lesson well earned, and hopefully learned..

If you get a chance to talk with them some more, remind them that it is this type of incident that fuels people to take away our rights to carry and he should either smarten up, or not carry...

Probably a graduate of one of the online "gun safety" courses.




.

[ClearSightTactical]

The gun went off

Please don't say that lol..unless it really did get caught on something...

Did it "go off" or was he fiddling with it and it discharged as intended?

[Ga9mm]

I'm not sure of exactly what caused the gun to fire. He was wearing jeans, and most likely had the hammer pulled back while in his pocket. I saw him yesterday, but he said he didn't want to talk about it, and he gave the gun to his dad. I guess he's done with it.