Your in a submarine and you have a torpedo locked on you. The torpedo was dropped from the air.......you are out of time. What do you do? You shoot it.

http://www.foxnews.com/tech/2017/04/13/these-new-kinds-bullets-are-lethal-underwater.html

Edit: Underwater rail gun in the future?

 

Since a .30 cal round out of an AK47 won't even reach over 2 metres under water i don't see this have any effect over longer distances.

 

Supercavitation has been around over half a century. The Navy demonstrated rounds that could be fired from a helicopter and destroy mines at depths up to about 150 feet. So just what is this article supposed to be telling us that is "new"?

If the quality of the proof-reading is any indication of the quality of the research ("with the extra drag bullets fast lose their velocity"), I won't hold my breath.

 

"Your in a submarine and you have a torpedo locked on you"

Pray for an afterlife. If we develop quickly maneuverable underwater guns (it seems impractical for a deep diving submarine) the countermeasures will just be armored torpedoes/weapons.

 

Supercavitation has been around over half a century. The Navy demonstrated rounds that could be fired from a helicopter and destroy mines at depths up to about 150 feet. So just what is this article supposed to be telling us that is "new"?

If the quality of the proof-reading is any indication of the quality of the research ("with the extra drag bullets fast lose their velocity"), I won't hold my breath.

Here's a press release from 2012. Not exactly new news, as you say.

 

Video.

 

Nice video -- thanks.

 

Put my head between my legs and kiss my a.. goodbye!