Bourne Identity, The (2002)
The Bourne Identity is a 2002 spy thriller that is the second adaptation of the Robert Ludlum novel of the same name (the first being a 1988 television film starring Richard Chamberlain as Bourne). The 2002 adaptation was directed by Doug Liman (Mr. & Mrs. Smith) and stars Matt Damon as Jason Bourne, a man suffering from amnesia who slowly discovers that he is actually a high level covert operative for the CIA. Compared to the 1988 adaptation, the newer plotline heavily utilized modern communication/computer technologies in the furtherance of the story arc. Damon would return as Bourne in two sequels: 2004's The Bourne Supremacy and 2007's The Bourne Ultimatum and the story would continue in 2012's The Bourne Legacy. Matt Damon would return for the fifth film Jason Bourne (2016).
The following weapons were used in the film The Bourne Identity:
A Swiss policeman carries a SIG-Sauer P225, of which Bourne swiftly disarms him and disassembles. Swiss Police have been known to use variants of the P225 (such as the P6).
SIG Pro SP 2009
When Jason Bourne (Matt Damon) visits the bank in Zurich, he gets a hold of his safety deposit box and, inside, finds several passports, cash and a SIG Pro SP 2009 pistol. Shortly thereafter, he takes the passports and money and leaves the gun in the box.
A member of US embassy security carries what appears to be a blued Taurus PT945, which Bourne manages to take from him during a struggle. Bourne tosses the gun in a trash can while making his escape. This is the gun that Bourne is seen holding on some posters for the film.
The blued PT945 appears in Castel's (Nicky Naude's) case with his passports and money. He is never seen using it. One of the assassins in the Paris Treadstone safehouse also has a suppressed stainless PT945, which Bourne disarms him of. Bourne then fires the PT945 and Walther P5C side-by-side, but the PT945 is upside down because he took it from the assassin very quickly and didn't have time to adjust his grip.
Walther P5 Compact
Jason Bourne carries a Walther P5 Compact in the Treadstone safehouse in Paris after taking it from the Professor (Clive Owen). After disarming an assassin armed with a suppressed Taurus PT945, Bourne uniquely carries the P5C and the PT945 side-by-side.
Heckler & Koch MP5K
During the search for Bourne in the U.S. Embassy in Zurich, the Marine Staff Sergeant can be briefly seen with a Heckler & Koch MP5K. (This is a continuity error, as he was carrying an M16 variant in other shots).
12 Gauge Double Barreled Shotgun
Jason Bourne (Matt Damon) uses a 12 Gauge Double Barreled Shotgun belonging to Eamon (Tim Duttin) to search for the Professor, after the Professor tracks him and Marie to the farmhouse in the French countryside. It appears to be a hammerless, side by side shotgun with a box lock action and a Churchill or Uplander stock and a splinter fore end. No other details can be made out.
There are hundreds of "Boutique" gunmakers scattered across Europe. They often use parts (locks and triggers) made by larger companies such as FN or Beretta and then assemble them with stocks and barrels that they manufactured. This has been the norm in Europe for centuries. Unlikely the make of the shotgun will ever be determined.
U.S. Marines arm themselves with various M16/AR-15-model assault rifles when searching for Bourne in the U.S. Consulate in Zurich. Strangely, all of the rifles seen in this scene appear to be civilian AR-15 variants, many of which are clearly "post-ban" versions (if you look on the armory wall, you can see many lack flash hiders and bayonet lugs - all signs of the "politically correct" black rifles that used to be sold in American gun shops). The ones with the short barrels are Bushmaster "Dissipator" carbines, an AR-15 variant that used to be sold only to LE agencies, but is now available to civilians in most states since the Assault Weapon Ban ended. Another Marine has a C7 Style AR-15 (i.e. with the brass deflector and A1 Rear Sight).
CQB-R / Mk. 18 Mod 0
IMI Galil MAR
When Bourne is in his apartment, Castel (Nicky Naude) breaks through the window, firing a Galil MAR aka Micro Galil, to try and kill Bourne and Marie. It is also very briefly seen in the hands of the Marines clearing the embassy in a very quick shot when two Marines kick in the door to room 304.
SIG 550 Sniper
The Professor (Clive Owen) uses a SIG SG 550 Sniper as his weapon of choice, first in Paris during a mission. He is seen with the rifle again later in the French countryside, after he tracks down Jason Bourne and Marie Kreutz to Eamon's home. The "suppressor" shown in the film is actually a Hogue OverMolded™ free-floating handguard for the AR15/M16 rifle. Even if the suppressor was functional, it would have to be attached to the end of the barrel in order to actually suppress the report of the weapon. Simply sliding it over the barrel would do absolutely nothing to the sound of the round being discharged. Also note that there are no provisions on the SIG 550 shown (IE; a threaded muzzle or some sort of mount attached to the barrel) to attach the "suppressor" depicted.
SIG SG 552
One of the Treadstone guards fires a SIG SG 552 at Bourne on the safehouse staircase. Bourne dispatches him with a single shot from the P5C.