eli5 – How do Projectiles that are made to shatter on impact not shatter in the barrel?

Question

I allways wondered, because the momentum that pushes them out of the barrel must be stronger than the one they have when they impact a target? so how do barrel launched grenades or paintsballs or other similar projectiles work?

In: 2

Answer 1

Time.

A projectile is accelerated down a barrel at *approximately* a constant rate. Let’s say the barrel is 1m long, and the projectile reaches 100m/s.

It will take 0.02 seconds to accelerate down the barrel, at 5,000m/s^2

Now, impact. This is against a person who’s skin yields 1cm.

Deceleration will take 0.0002 seconds, with an acceleration of *500,000m/s^2*

Obviously the deceleration is a lot more likely to deform the projectile.