Robert Rath (Sylvester Stallone) and Miguel Bain (Antonio Banderas) both use integrally suppressed Ruger Mk I pistols. Bain comments to Rath that he began to carry the "Ruger .22" once he found out that it was the same weapon Rath used in his assassinations. Electra (Julianne Moore) also uses Rath's Ruger on several occasions. It is identified as a Ruger Mk I as opposed to the Mk II as the Mk I has fixed sights, as do the Rugers used in the film. ---The standard Ruger .22 has always been available with fixed sights. It could be a MKI or MKII. -- All of the Ruger pistols are MK II - they have the slide release - with fixed sights and they are not integrally suppressed they have screw on cylinders.
When Robert Rath (Sylvester Stallone) is walking one of his marks, an ex-hitman named Ketcham (Muse Watson), through a forest. Later, Rath ejects the magazine out of the suppressed PP and hands it to Ketcham, stating "it's chambered". Ketcham then uses his own Walther PP to kill himself, saying "goodbye old friend" before shooting himself in the head.
Claridge Hi-Tec/Goncz GC
Miguel Bain (Antonio Banderas) uses a suppressed Goncz GC carbine in the cemetery to kill Alan Branch (Steve Kahan) at the funeral. During his escape from police custody, he retrieves the weapon (which is oddly still loaded after his arrest) and uses it while in the taxi with Rath. (It may also be a Claridge LEC9).
Beretta 92FS
Several of Alan Branch's bodyguards (David Dollase and Jim Graham) fire Beretta 92FS pistols at Bain after he takes out Alan Branch in the cemetery. A male Interpol agent in the hotel (Dave Young) that Bain assassinates in the hallway also has a Beretta, albeit suppressed.
Smith & Wesson Model 10
The policemen arresting Miguel Bain at the cemetery carry Smith & Wesson Model 10 revolvers.
Heckler & Koch USP
One of the Interpol agents posing as a Dutch buyer carries a suppressed Heckler & Koch USP.
SIG-Sauer P226
Another Interpol agent posing as a Dutch buyer carries a suppressed SIG-Sauer P226.
Glock 17
The other Interpol agent posing as a Dutch buyer carries a suppressed Glock 17.
Sphinx AT-380M
Miguel Bain (Antonio Banderas) uses a two-tone Sphinx AT380 with a suppressor as he breaks into the room with the Interpol agents.
Remington Model Seven
Miguel Bain (Antonio Banderas) uses an integrally suppressed Remington Model 7 compact tactical rifle with a Leatherwood ART scope and thumb cut stock while waiting for Robert Rath in San Juan. Electra (Julianne Moore) eventually gets her hands on the rifle and fumbles to use it, but manages to take a few shots at Bain. She later gives it to Robert Rath (Sylvester Stallone) who disables it by removing the bolt. This rifle differs from the classic Remington 700 action in that the receiver is shorter than a standard length and takes shorter but still powerful cartridges. It is designed to be a tactical bolt action rifle that is compact and can be easily fired from minimal cover. The 'sportsman' version is the Predator and CDL and is promoted as a rifle for "thick cover hunting".
MAC-10
The guard at the San Juan bank carries a suppressed MAC-10. Why a bank guard needs a suppressed submachine gun is never explained.
Heckler & Koch P9S
Rath's ex-partner Nicolai Tashlinkov (Anatoli Davidov) confronts him, Electra, and Bain in the finale with a suppressed Heckler & Koch P9S.