Depth charge 40mm ammunition

This interesting grenade, manufactured by Bulgarian firm ARCUS Co., is designed to combat frogmen. The AR476 is fired from standard 40mm launchers at the area where combat divers are suspected to be underwater. When the projectile hits the water, a time deployed fuse is activated.

Many thanks, again, to Lusaka for the photo and info.

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Matt Groom

    This is actually a brilliant idea! It’s a lot better than peppering the water with MG fire.

  • Great potential for a bit of fishing, too!

  • abc123

    You can’t even use modern bullets to pepper the water, they tried this at mythbusters and I think 5.56, 7.62×51 and .50 BMG failed to get more than 1 meter down.

  • HotelCoralEssex


    Woodleigh is now selling hydrostatically stabilized (cavitating) bullets in several diameters… 0.308″ among them.

  • Entropy

    IIRC from Mythbusters and other investigations, most supersonic bullets are smashed to pieces when they hit water. Pistol rounds work fine, and a 9mm will still be dangerous at 10m, whereas (as abc123 said) rifles are pretty useless unless you’re using them as boomsticks.

    The grenades seem like a good idea, but I’ll be frank: how often are frogmen encountered? Last I heard there were a few incidents of them operating in the Cold War snooping on warships, but they’re a very rare problem. This grenade seems like a very niche solution to a very rare issue.

    Now, grenade fishing on the other hand… 😛

  • j

    sucks to be a combat diver!

  • hagbard hednig

    Useless, but interesting.

    Honestly, if you see combat divers, haul ass out of there and use your RADIO to call in something bigger. CD:s are expensive and usually come with a *load of fire support. You shoot at them and you’ll have the enemy navy’s biggest guns turning your way in seconds.

    “Frogmen”/divers are usually not seen.

    They use rebreathers so you never see any bubbles. They can swim in, attach explosives to a ship and swim away before sinking your battleship.

    There are sensors which would detect divers, but those are what you’d see on a modern littoral warship, and would be integrated with the ship’s other systems rather than with the foot soldiers guarding it.

    I the case of combat divers (reconnaissance/sabotage and so on), again a foot soldier wouldn’t see bubbles and shoot a grenade into the water.