The following weapons were used in the film A Bittersweet Life:
Stechkin APS
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.
Moo-Sung is armed with a Smith & Wesson Centennial revolver during the finale. Another of Baek's thugs is seen loading one by spinning the cylinder and flicking his wrist to the right in order to push the cylinder back into place.
Sun-Woo's friend Min-gi is armed with what looks like a Smith & Wesson model 36 at the beginning of the film. In the slightly altered Director's Cut, there is an extra scene not present in the theatrical version before Sun-Woo and Min-gi confront Baek's men where Min-gi is seen checking the revolver.
Error creating thumbnail: File missingSmith & Wesson Model 629 Classic - .44 MagnumError creating thumbnail: File missingThe brother retrieves a S&W 629 Classic, on the far left, from an arms cache. Two other revolvers are present in this shot, one might be the same prop used on several film posters featuring Sun-Woo. However, they are somewhat out of focus, making them difficult to properly identify.Error creating thumbnail: File missingThe brother fires the Smith & Wesson Model 629 Classic.
Steyr SPP (mocked-up as Steyr TMP)
The Steyr SPP, mounted with a front grip and converted to automatic fire to give the appearance of a Steyr TMP, is used by the arms dealer Myung-Gu before Sun-Woo kills him, taking the gun for himself and using it for the rest of the film.
One of Baek's thugs is seen loading what looks like a TP9 in the finale. It could however be another modified Steyr SPP. He is later seen hiding behind a corner, TP9 at the ready, but is killed by the gun dealer's brother before he can fire it.