- Feb 2011
With the onset of gunpowder weaponry, the need for hard-hitting crossbows declined. Arrow shooting firearms using uncorned Medieval gunpowder could shoot at over 800 joules, compared to the 249 joules of the typical Han crossbow. This arrow-shooting firearm was further improved when the Chinese learnt from Vietnamese design after the early Ming conquest of Vietnam. They started used a sabot to improve the gun’s accuracy. The niche for armor penetration was taken by projectiles shot by the force of gunpowder. One can see this by first reading the early Medieval Tongdian and Medieval SongShi and then the Reinassance Ming Yinzong Shilu. In these instances, the Medieval sources mention that crossbows start shooting at long distances whereas bows start shooting at close distances. But by the Ming era, it was arrow-shooting firearms which started shooting at long distances, and it clearly replaced the crossbow in this regard.
The early Medieval Tongdian says: 其弩手去贼一百五十步即发箭，弓手去贼六十步即发箭。若贼至二十步内，即射手、弩手俱舍弓弩，令驻队人收。其弓拿手先络膊，将刀棒自随，即与战锋队齐入奋击。
The crossbowmen fire at the bandits (enemy) when the distance is 150 paces(225m), the bowmen fire at the bandits when the distance is 60 paces (90m), if the enemy come within 20 paces, the crossbowmen and the bowmen puts down the bows and crossbows and order others to collect them. The crossbowmen and bowmen each have a sword-staff, and will pick them up and attack with a shout along with the vanguard companies…..
Medieval era Wulin says: 每战，以长枪居前，坐 不得起；次最强弓，次强弩，跪膝以俟；次神臂弓。约贼相搏至百步内，则神臂先发；七十步，强弓并发；次阵如 之…..
In every battle, the long pikes are at the front. They are sitting and not standing up. Then comes the strong bows, then the strong crossbows, all kneeling. Then comes the Divine Arm crossbows. When fighting bandits within 100 paces, the Divine Arm [crossbow] fires. Within 70 paces, the strong bows fire, and the next formation does the same……
Ming Yinzong Shilu, however, clearly shows that firearms replaced the tactical role of long-powerstroke crossbows: “敌在百步之内，神机枪射之，五十步内，弓箭射之，二十步内，牌枪刀迎击”
"when the enemy is within 100 paces, the [arrow shooting] divine engine guns fire, within 50 paces, the bows fire, and within 20 paces, the shields, pike, and swordsmen engages to attack”
'Divine Gun' from the WuBeiZhi
I'm afraid I remembered wrongly when I said "arrow shooting firearms using uncorned Medieval gunpowder could shoot at over 800 joules". A gun such as the "Divine Gun" shown above should be able to shoot at roughly 1600 joules or even above that.
The number can be derived from an experimentation with the Loshult gun.
Source: "Fitting Round Pegs into Square Holes, an analysis by Klaus Leibnitz"
The article says:
The arrows were forced into the cylindrical part of the barrel with a wooden mallet until the fletches almost touched the muzzle.
The article continues to say:
The third shot, using 50 g of Lille gunpowder and arrow #4 fired the arrow with a velocity of 87 m/s to a distance of 360 m.
The article described arrow #4 as:
"two fletches and a shorter head weighted 420 g"
The article described the gunpowder for this particular shot as thus:
"Originated in Lille, France and dated 1350. It consisted of a mixture of 55.6% saltpetre to 22.2% sulphur to 22.2% charcoal." The gunpowder mixture substituted calcium nitrate with commercial grade potassium nitrate due to moisture in the calcium nitrate, even though calcium nitrate "reacts more strongly in a gunpowder mixture". The substitution was because the calcium nitrate available to the project was too moist.
Ergo the handgun shot an arrow weighing 420 grams at 87 m/s, which equates to 1,589.5 joules. And keep in mind an arrow needs several times less joules than round bullets to penetrate the same armor plate.
The Loshult gun "weighs 9.06 kg and is slightly over 300 mm long". As of far, the only early Ming handgun with a sabot still found inside, dates to 1415. It was 8.9 kg, ergo nearly the same weight as the 9.06 kg Loshult gun.
Vietnam: Borderless Histories, on pg 92 says: "Chinese handgun of 1415 (length 42.6 cm, muzzle bore diameter 4.4 cm, weight 8.9 kg) with wooden wad. The Chinese words mean (from left to right) "gunpowder," "wooden wad," and "iron bullets." When unearthed they were still in the barrel of the gun. Reprinted from Cheng Dong and Zhong Shaoyi, Zhongguo gudai bingqi tuji, 231."
Also the tested Loshult gun was already said to be not designed for shooting arrows, yet it still achieved nearly 1,600 joules. The article says: "The Loshult guns by its design and construction not suitable for shooting arrows. The evidence available indicates that it was used to shoot iron pieces like a shotgun.... Two of the alleged gun-arrows would, as far as dimensions are concerned, almost fit the Loshult gun, but provide neither adequate gas-seal nor guidance to the arrow." Whereas the Shen Qiang was designed to be used both as an arrow shooter and as a shotgun, not just a shotgun.
The sabot technology started in Vietnam, was exported to China, and eventually arrived in Korea as well. The Korean Seungja Chongtong (승자총통 ) used the sabot to either shoot a single arrow or to spray out multiple projectiles at once similarly to a shotgun.