Wu Lei Shen Ji (五雷神機), San Jie Shen Ji (三捷神機) and Wan Sheng Fo Lang Ji (萬勝佛狼機)

UPDATED MAY 9, 2022

Wu Lei Shen Ji (五雷神機, lit. 'Five thunders divine engine')

Drawing of a Wu Lei Shen Ji, from 'Wu Bei Zhi (《武備志》)'.

Wu Lei Shen Ji is a "proto-matchlock gun" with five rotating gun barrels, which allow its user to fire multiple shots in rapid succession. Designed at the turn of the seventeenth century in an effort to upgrade obsolete Chinese handgonnes to comparable standard of matchlock arquebus while retaining simplicity and high rate of fire of older handgonne designs, Wu Lei Shen Ji is upgraded with gun sight, a wooden pole that bends downward at one end to facilitate aiming, as well as a simple thumb-pressed matchlock mechanism, likely a serpentine (slow match clamp) mounted on a flat spring.

Despite the aforementioned improvements, Wu Lei Shen Ji is not considered a true matchlock gun, as it still retains handgonne-style gun barrels which lack a flash pan and are forged with less sophisticated methods. In addition, it is used in a very different manner from typical arquebus or musket—instead of bracing the gunstock against one's right shoulder and using right index finger to pull the trigger, the gunner of Wu Lei Shen Ji tucks its wooden pole under his right armpit, and uses his left thumb to press the serpentine into touch hole to fire the weapon.

Wu Lei Shen Ji also shares many similarities with Xun Lei Chong (迅雷銃) including the exact same barrel length and calibre, which suggests that one might have inspired the other.

Shan Jie Shen Ji (三捷神機, lit. 'Three triumphs divine engine')

Drawing of a San Jie Shen Ji, from 'Wu Bei Zhi (《武備志》)'.

San Jie Shen Ji is identical to Wu Lei Shen Ji in every respect except that it has only three gun barrels. It is also quite similar, though possibly unrelated to, other triple-barreled matchlock handgonnes such as San Shen Tang (三神鎲).

Wan Sheng Fo Lang Ji (萬勝佛狼機, lit. 'Ten thousand victories Frankish engine')

A Wan Sheng Fo Lang Ji, three loading chambers and a leather chamber holster, from 'Wu Bei Zhi (《武備志》)'.

Wan Sheng Fo Lang Ji is a variant of Wu Lei Shen Ji/San Jie Shen Ji that uses long loading chambers—essentially pre-loaded, quick-exchangeable gun barrels—to achieve high rate of fire. Despite being named after, and inspired by, breech-loading swivel gun, Wan Sheng Fo Lang Ji is loaded from the muzzle rather than from the breech (which eliminates the gas leakage problem that plagued pre-modern breechloaders). It still retains the wedge used by breech-loading gun to lock the chambers in place however, although in this case the wedge is used to prevent loading chambers from sliding out of gun barrel when the gunner points his weapon downward.

Being a single-barreled gun, Wan Sheng Fo Lang Ji is lighter and better balanced than its front-heavy, multi-barreled counterparts, and trades a modicum of firing rate for better capability to keep up sustained fire (as its spent chambers can be individually reloaded).