Underwater Shooting

[ViggoG]

Folks,
It just seems to me that we have a Catch 22 situation in Underwater Ballistics Testing.
The very objectives of underwater shooting are self defeating. That is to say: Every time the projectile displaces its own mass of fluid the velocity is reduced by approximatly 50%.
So we have the high velocity slug reduced to practically NIL in a very few feet.
That is why a Ballistic recovery tank of 6 feet in length will stop all but the very heavy high secional density projectiles such as the 50 cal machine gun.
And even that will travel less than eight feet under water.
The best sucess would probably be attained with a very high sectional density projectile such as is now being used for underwater spear guns, something on the order of stainless steel 5/16" dia X 30" to 36" in length. That would have a sectional density capable of displacing a 15 ' to 20' column length of water. still not as effective as a good 9' long Hawain Sling
An effective barrel length of less than 1.5" would probably be quite effective as a launcher if a very slow burning propellant were used.
Just my thoughts on ths subject .
ViggoG