SOCOM bought some bullets from a company called DSG Tech that are engineered for shooting underwater (or through water), giving rise to speculation that they have a renewed interest in shooting people underwater. The solid copper model is supposedly good for 15 meters penetration through water and the tungsten core version is double that.


I *think* this is the same projectile

The bullets are called "supercavitating" and apparently it comes down to a blunt-ish meplat that causes enough cavitation to envelop the rest of the projectile in air bubbles as it flies through the water, like the Sovietski Shkval cavitating submarine-launched torpedo.

Also similar to an anti-mine system the navy was tinkering with about 20 years ago. It was a sabotted fin-stabilized 30mm round fired from the same chain gun as the AH-64 Apache uses. It was designed to be fired from anti-submarine copters flying over the water (naturally) but to still have enough penetration to reach down to the depth that a static mine might be lurking at (which basically means the same as the draft of a warship).


Mk 258 Armor Piercing, Fin Stabilized, Discarding Sabot-Tracer (APFSDS-T)
Anti-Mine Projectile Hydroballistic Ammo 30mm Ammunition


There's interesting videos at the link at top, including shooting (from what I think is a SCAR) it in a plastic swimming pool (which apparently was patched with duct tape from earlier tests) on high-speed video. The mfgr's site is here..

Also interesting that they're engineered for adequate terminal performance both in and out of the water, and it's armor-piercing. There's a video of it going through 13 blocks of ballistic gel, and I don't know the length of each but I'd guess 18 inches.

But I'll be what it ain't is cheap.