Sun-Woo (Byung-hun Lee) uses a Stechkin APS pistol for much of the latter half of the film, stealing it from a weapons dealer who claims it is the "finest gun manufactured in Russia". Although the Stechkin is select fire, Sun-Woo only fires it in semi-automatic.
The Brügger & Thomet TP-9 submachine gun, converted to automatic fire, is used by one of the weapon dealer's accomplices after their deal with Sun-Woo goes south. After the man is killed, Sun-Woo takes the TP-9 and uses it during the film's finale.
Two thugs working for the mobster Mr. Baek use Norinco Type 56-1 rifles during the finale, firing them wildly at Sun-Woo before they are killed.
Error creating thumbnail: File missingNorinco Type 56 (Imported into the U.S. as the Norinco AKS-47 or AKS-47 Sporter) - 7.62x39mm. Rather than having the underfolder pig sticker Bayonet assembly, this has the standard Bayonet lug underneath the gas block as the AKM and later variants.