Ming bowl-mouth hand cannons and 'General' cannons

Timeline

1. 1421–1422Beijing · BeijingAfter the Yongle capital move to Beijing in 1421, the court allocated bowl-mouth hand cannons and larger-caliber guns to the Forbidden City, the Imperial City, and the nine gates, forming a capital firepower network together with the Shenji Camp; the Ministry of Works and Imperial Household casting offices oversaw production and acceptance.
2. c. 1424–1428Jizhou · TianjinFrom the late Yongle to early Xuande reigns, bowl-mouth hand cannons and large-caliber bronze guns popularly called 'General' cannons continued to be issued to the Nine Frontiers garrisons and naval warships for city defense, river defense, and close-range bombardment; cast inscriptions commonly bear the Yongle, Hongxi, and Xuande era names.
3. 1429–1430Beijing · BeijingDuring the Xuande reign the court continued the Yongle firearms policy, inspecting, recasting, and drilling the existing bowl-mouth hand cannons of the capital and the Nine Frontiers, training jointly with the Shenji Camp's guns to consolidate the northern frontier defense system.