Hwacha-doing? February 16, 2009 ~ RockyMountainNavy The Hwacha is an ancient Korean artillery piece that fired multiple rocket-propelled arrows. Recently, Mythbusters took it on to see just how effective it was… Amazingly, it works! Share this:TwitterFacebookLike this:Like Loading... Published by RockyMountainNavy Wargame Grognard, Boardgamer, and Sci-Fi RPG playing since 1979. View all posts by RockyMountainNavy