The Young Dragons(1974)

Overview:

Powerful mobster Leung, protected by the dangerous Huan Fai, sells 200 Japanese weapons and ammo to a Chinese gang. He uses smuggler Luy Fu to bring the weapons but small-time thief Kim and his gang heist the shipment and dump the cargo into the sea. Meanwhile, Kim befriends Fan Ming, an undercover police office from Shanghai investigating Leung's crimes.