Awesome documentary. Love it. Bowhunter and bow builder here. Learned archery and bow hunted way before going into guns...
BTW, Korea is basically still the epicenter of almost all things archery today. Hoyt and Samick, two of the leading names in modern bow technology, have their factories and engineering departments based in Korea. Samick is actually a Korean company with franchises in China, USA, and the rest of the world. Hoyt is co-owned I believe. Korea/USA. Fiberglass is the modern equivalent of horn, and is the main reason why modern, high tech, and almost fully weatherproof recurve bows made a comeback around 1940 or so. Before fiberglass, the only way you can make a recurve bow impervious to the elements was by making them out of spring steel, bronze, and brass. The main reason why the Mongol invasion of Vietnam failed spectacularly was because the Mongols' traditional sinew, glue, and horn bows unraveled in the Indochina heat and humidity and became useless. Vietnamese bows were made from steel, and Vietnamese sharpshooters killed the ever living fuck out of the Mongols... Chinese bows around the same time were made from steel and brass as well. During the Ming Dynasty, that enabled Chinese troops to go all the way into the grasslands of Transoxiana, crush a Turkish revolt, and then go back to the south, pick up their payrolls in Guangzhou, and then off to Hong Kong and Mindanao to get roaring drunk and impress pretty Pinoy ladies by shooting apples off each others' heads, all with the same standard field kit...
Now if you want something to really fuck with your mind tonight, check out this Hoyt torture test video right here... 1500 dry fire shots are standard proofing for each Hoyt bow before leaving the factory in Korea... This kind of shit would have wrecked any other compound or trad bow on the first attempt, much less 1,500...