Why is exit wound in a rifle gun shot injury bigger than entry wound?

[scilearner]

Hi,

Generally if u see a post mortem skull after a rifle shot injury, exit wound is bigger than entry wound. Shouldn't the bullet lose lots of its energy when coming out, hence smaller wound. Maybe it is spinning or something, but I want to get others views. Thanks

[moreinput]

Fragmenting bone, bullet type and caliber, and kinetic energy.

 

When the bullet hits a target it strikes at full force depending on the distance and caliber, hence a cleaner entry point. When it exits, it has lost energy which can cause it to force the bone outward, rather then pierce it cleanly. It is also important to bear in mind that results will vary depending on the type of bullet, does it fragment ETC.

 

Having grown up hunting, you learn to match your bullet and gun to make sure you have a clean in and out. Although I did more bow hunting then rifle the dynamics were still the same. Arrow head type, draw weight ETC.

[ewmon]

The entry point experiences the bullet at its most aerodynamic quality, which enters with the least resistance. Under some circumstances, the entry wound may not look much more than a dimple and may not bleed (especially if death occurs quickly). Bullets mushroom as they plow through tissue.

 

 

The transfer of energy produces secondary projectiles (bone fragments, as moreinput mentioned), disrupting more tissue that tends to be cone-shaped, spreading outward from the bullet's trajectory.

 

I don't recall spinning having much effect, except that an unstabilized bullet (perhaps not enough spin) might tumble and "keyhole" the body (ie, hit it pretty much sideways), which makes a nastier entry wound (that is, more energy transfer — and damage — than usual).

 

A bullet does lose a lot of energy, which transfers to the tissues and sets them in motion.

[J.C.MacSwell]

The entry has the backing of something fairly solid. The exit has the backing of... just air

[Ihcisphysicist]

Or in a simple way, when the bullet is fired it carries power along with it, when it touches or pierces objects the power/energy is transfered to the obect thus the energy disrupts the molecules of the object in a chain of disbursement of the energy until it diminishes and so as it passes it leaves a bigger impact all the way.