Originally Posted By: Kuzushi
Ammo questions...
It was always my understanding... ... would those expansion forces be enough to expand the bullet before it left the barrel possibly damaging the firearm and potenially causing other damage? something to think about...

As an aside, glocks have an optional fluted firing pin cup for firing underwater. Most people don't have an 'operational' need for this.


Kuzushi,

Urban Myth all the way. I have shot or seen shot many different types of HP ammunition. When recovered, the bullet is undeformed. Firing into water is the most common way for forensics labs to recover tool marks on a round. The reason many use GI FMJ is that it is sealed both at the primer and at the case neck. Most commercial ammo is not. It may fail to fire after a few minutes to a few hours in the water.

The Glock amphibious firing pin is useful as it prevents the water from blocking firing pin motion. It does not always do it, but it can. More often when you get out of the water with a wet pistol. The flutes allow the water to drain quickly. That is the primary design concept of the pin, not for use underwater since the pistol becomes only a contact weapon below the surface.

Respectfully,

Jerry