Romeo Must Die
The following weapons were used in the film Romeo Must Die:
Several nickel-plated Taurus PT92s can be seen in the hands of gangsters throughout the film.
Mac (Isaiah Washington) is seen carrying a Walther PPK/S in an ankle holster as one of the many guns he carries throughout the film. With the two revolvers and the SIG-Sauer P226, that makes four guns he seems to carry around.
Desert Eagle MK VII
Maurice (Anthony Anderson) uses a chrome-plated IMI Desert Eagle with a black safety and hammer. In one scene where he tries to draw this gun on Han (Jet Li), Han disarms him and throws the gun away. Maurice later gets another one (or maybe just happens to find the gun Han threw away later). This gun is also used by a gangbanger in the club at the beginning of the movie.
Smith & Wesson Model 629
In addition to his SIG and his Walther, Mac also carries a pair of Smith & Wesson Model 629 revolvers with custom grips.
Smith & Wesson Model 60
Smith & Wesson 5906
A Smith & Wesson 5906 is used by one of the Asian assassins on motorcycle, and appears again later in the film.
A Wildey Magnum auto pistol is loaded in a car by one of the Asian gangsters before they storm the club.
A Vz 61 Skorpion SA is seen at the beginning of the movie in the hands of Kai's gangsters.
Heckler & Koch MP5A3
The guards in the Chinese prison carry Heckler & Koch MP5A3 submachine guns along with the AKs.
Heckler & Koch MP5K (and PDW)
Heckler & Koch MP5Ks are seen in the hands of the Chinese gang and the black gangsters. Both sides had the PDW stock. The NFL bodyguard had a regular MP5K with a brass catcher at the end of the movie in the helicopter.
A Cobray M11/9 is used by one of the Asian assassins on a motorcycle. It seems to be the same nickel-plated Cobray also seen in American Dragons (which makes sense because Rob Fournier was the armorer on this film and that one, according to the credits).
Olympic Arms K23B "Suitcase Gun"
A bodyguard protecting Vincent Roth (Edoardo Ballerini) at the end uses a compact assault rifle hidden in a suitcase. This is a modified Olympic Arms K23B AR-15 "stubby" with a cut-down front sight and a suitcase-style carry handle affixed to the flattop upper receiver.
Olympic Arms K3B Commando
When the Asian and black gangsters all have guns drawn on each other at the beginning in the club, Silk (DMX) breaks up the fight by firing a shorty M4-type weapon into the ceiling. He then says, "Guns don't kill people, people kill people". This weapon looks similar to the Colt Model 933 (AKA the "M4 Commando"), but it is actually an equivalent from the Olympic Arms K3B series. It is recognized as an Olympic Arms rifle by the white lettering on the lower receiver and the four-prong "Phantom"-style flash hider.
Silk's bouncers in the club are seen using Colt XM177E2 carbines; however, the weapons look fake and plastic, which suggests they might be airsoft guns (unlike Silk's M4, which is definitely a real blank-converted weapon).
Norinco Type 56-1
The Chinese prison guards mostly use Norinco Type 56-1 assault rifles.
A Franchi PA3/215 is seen in the hands of a bodyguard.
ZB-53 / Vz.37 7.92mm machine gun
A Czech 7.92mm ZB-53 / Vz.37 machine gun is seen in the Chinese prison.