The following weapons were used in the film Fulltime Killer:
O (Takashi Sorimachi) had two Beretta 92FS in Macao, a standard and a customized one with a compensator and extended magazine. One of the target's bodyguards also had one. Police officers were seen armed with these as well. When escaping from his hideout in Singapore he had another one with wooden grips.
A thug was using a suppressed Walther P99 in O's flashback.
Smith & Wesson Model 60
Another assassin targeting Lok Tok-Wah used a Smith & Wesson Model 60.
O used a Colt Python but said it was a fake that shoots blanks to distract some thugs.
Smith & Wesson 686
In a continuity error, during the shootout in the parking lot, O's Python turned into a Smith & Wesson Model 686.
Numerous variants of the Remington Model 870 Shotgun was seen throughout the film. Lok Tok-Wah (Andy Lau) used a sawed off one in his opening scene in a police station hidden in a bouquet of flowers and then another one in downtown Hong Kong. O used a full size 870 with a vertical foregrip and a hollowed out stock when escaping from his hideout.
O had a Franchi SPAS-12 in his room and a police officer used one when clearing the building. Both ones used had no stock.
Lok Tok-Wah used an Uzi during the final shootout with O.
Heckler & Koch MP5A3
In O's hideout, he had an Heckler & Koch MP5A3 on his wall.
Heckler & Koch MP5K
Also on display in O's decoy apartment is an MP5K.
Colt Model 727
In O's decoy apartment, he had a Colt 727 on display. Another was seen in his hideout with the handguard removed.
Lok Tok-Wah tried to teach Chin how to shoot and trained her with an M16A2 fitted with a suppressor, scope, bipod and 20 round magazine.
Heckler & Koch G3
During the Macao job, Lok Tok-Wah used an unknown G3 variant on O. Possibly the G3A3 variant.
In O's real hideout, he had a custom AR-15 in a sniper's configuration with scope, bipod and special pistol grip. The hand guard appeals to be the Bakelite variant that is seen in an early AR-15 design. Chin uses it during their escape.
Lok Tok-Wah used a Barrett M82 to cover O and Chin as they escape from the police.