Instantaneous Discharge Matchlock (瞬発式火縄銃)
Instantaneous discharge matchlock is an ignition system for matchlock guns, which are represented by Japanese hinawa-ju (literally, fire rope gun).
The lock mechanism is released by pulling the trigger and a burning slow match strikes the primer in a flashpan by a spring to set off an explosion. There is no time lag between triggering and percussion, therefore this type of matchlock is suitable for sniping. On the other hand, the system common in Europe, Islamic countries in Western Asia and China is called gradual discharge matchlock. A serpentine holding match is kept at a lifted position by means of a spring, and the serpentine is slowly brought to the flashpan as the trigger is pulled, and the fire on the match contacts with the priming powder in the pan to make an explosion. When the trigger is released in the middle of aiming, the serpentine, which is resisted by the upward force of the spring, returns to the lifted position. Although the accuracy is lower, this type of gun is suitable for hunting because it has small risk of accidental discharge and can be carried with burning match. In Europe, musket troops traditionally formed a line and discharged in a volley in the same direction to lay down a barrage at orders of a commander, therefore accuracy rates were of no particular concern.
This type of matchlock was invented in Southern Europe in the 16th century, but the firing mechanism which makes a match strike the flashpan by means of a spring action to the flintlock which produces a spark by striking steel with a flint, and was used only for a short period. During the short period, however, the European-style instantaneous discharge matchlock introduced to Southeast Asia by the Portuguese was improved and the instantaneous discharge matchlock called Malacca-style was invented. According to one theory, barrage tactics were less effective in the forest area of Southeast Asia because of obstructive trees, and for that reason, the instantaneous discharge ones suited for sniping became popular and accepted. This Malacca-style matchlock of Southeast Asia was introduced to Japan. This style of gun naturally fit in the tactics for shooting war using traditional Japanese archery and became prevalent in Japan. Although it is generally believed that the Portuguese introduced matchlocks to Japan and that the European-style ones were brought in as they were, most Portuguese called Nanban-jin (literally, southern barbarians) in Japan at that time were actually not directly from Portugal. Most of them were descendants of Portuguese who settled down at the footholds secured in India or Southeast Asia and married local people some generations ago. It is therefore not strange that the guns imported into Japan were Malacca-style. With the advance of historical study, the most likely theory is now that the introduction of guns into Japan simultaneously took place at various places in southwestern Japan during a short period by wako (Japanese pirates) involved in trade with Southeast Asia.
European ones might have been imported via a different route afterward. In Japan at that time (the Sengoku period [period of warring states]), unlike in Europe, there were no tactical ideas of using artillery barrage to hold back enemies. At the time of a battle in Japan, gunners (teppo-ashigaru, foot soldiers fighting with firearms) were organized in small groups under the command of high-ranking warriors, and these units vied for exploits of war, therefore accuracy rate of individual gunners was of high concern. It is considered that there was no room for gradual discharge matchlock with low accuracy to take hold in Japan for that reason. Furthermore, in the pacific Edo period, matchlocks were mass-produced for 'gunnery,' a part of martial arts that became an education for samurai warriors and for hunting to exterminate mammalian pests, therefore the accuracy rate was valued in a sophisticated way.
Under the gun-related circumstances in Japan, wheel lock and flintlock guns had already been imported during the Sengoku period, but in spite of the fact that they had a similar explosion mechanism to that of instantaneous discharge matchlock, the spring action was so strong that the barrel was unstable, and there was a time-lag between sparking and ignition, which caused a low accuracy rate. As a result they failed to take root in Japan and the matchlock guns were used until they were cleared out in the upheavals in the closing days of the Tokugawa shogunate.
However this is now in favor of Japanese competitors in the event of matchlock of muzzle loader since most European competitors use Japanese matchlock which is familiar to Japanese ones, it is easier for the Japanese to obtain medals.