Fox (Angelina Jolie) packs a custom Safari Arms Matchmaster 1911 clone with a Wilson 10 round magazine, Parrish 1911 Bushing Compensator (which would cause a muzzle flash that would likely blind her in low-light situations), engraved ivory grips, and custom engraved slide throughout the film. The official website of the film describes: "Fox's weapon of choice is a custom .45 caliber SAFARI MATCHMASTER semi automatic pistol. Although she prefers its lightweight versatility, she is a virtuoso with any firearm which exists".
CornerShot
During the shootout at the pharmacy, Fox (Angelina Jolie) uses a CornerShot device together with her Matchmaster, allowing her to look and shoot around corners during a shootout with Cross (Thomas Kretschmann) in the grocery store. It's obviously based on the real CornerShot, but there isn't a type like the one used in the film.
Custom Beretta 92S
Mr. X's (David O'Hara) sidearm used in the opening sequence is a customised Beretta 92S. It has ornate grips and a compensator.
Later it is given to Wesley (James McAvoy) to shoot the wings off of flies, to prove he is gifted. Sloan (Morgan Freeman) refers to it as an "Imanishi 17," though no known make or model of firearm exists. Wesley hides the Beretta in the toilet and after leaving it there to soak for about a week, he retrieves it and uses it while chasing Cross through the parking garage, accidentally shooting The Exterminator (Konstantin Khabensky) instead. He then uses it for the shootout on the train with Cross, firing several shots at him before he drops it during the crash and draws his Star Ultrastar. In one of the wallpapers, Wesley can be seen holding a 92FS with same customisations.
Mauser C96 - M712 "Schnellfeuer"
Sloan (Morgan Freeman) is seen armed with a M712 "Schnellfeuer" or "Fastfire" (in German), the select fire version of the C96 "Broomhandle" Mauser with a detachable box magazine instead of a fixed internal magazine loaded with stripper clips.
Beretta 92FS
An officer is seen armed with a Beretta 92FS when Fox's car flips over him. Wesley is seen wielding several during the shootout in the mill.
Browning Hi-Power
Wesley (James McAvoy) is seen using several Browning Hi-Power pistols during the shootout in the mill using both his and some captured from assassins.
Flintlock Pistol
Mr. X (David O'Hara) uses a flintlock pistol mocked up to look like a magazine-fed gun to curve a bullet and take out a man on the roof of the building. Fox uses one to fire at Cross during the car chase. One is seen disassembled on a table in the mill.
Glock 17
One of the police officers is seen armed with a Glock 17 when Fox's car flips over him.
Wesley (James McAvoy) uses a Heckler & Koch USP Compact with a silver outer barrel as his weapon of choice throughout the movie and for his first two kills and his first bullet curve. He also briefly uses one during the final gunfight at the textile mill. But before taking the UMP from a guard, we can see that its changes into a Jericho 941. It is most likely the 9mm or the .40 S&W version. Because Wesley fires 13 rounds. The possibility of this being the .40 is because there might be one bullet in the chamber, making 12 in the mag and one in the chamber. Or he didn't, and fired 13 rounds with a 9mm version. It is of course, not the .45 since the .45 has a different frame under the rail. In the extended scene, Fox gives her USP compact to Wesley for him to know what it feels like to put a bullet in a body. So it might be Fox's Backup gun. And in the extended scene, Wesley has a revealed hammer.
Pekwarsky (Terence Stamp) uses a tutone (stainless frame, blued slide) Jericho 941 "Baby Eagle" to hold on Wesley in the castle. Full black Baby Eagles are also seen in the hands of multiple other people, usually just briefly as continuity errors. Wesley most notabley uses several during the Mill shootout, one of which he uses to kill The Butcher (Dato Bakhtadze) by firing a steel poker rod into him after he acidentally jams it down the muzzle of the gun. In reality, this would not fire the rod like a big bullet, but become an obstruction and blow up the gun.
Jericho 941 FBL Compact
Cross (Thomas Kretschmann) uses a Jericho 941 FBL Compact "Baby Eagle" as his weapon of choice in the film. The rounds his gun are shown firing are far too large to be chambered in the breech or to fit in the magazine. Wesley can also be seen using one in the final gun fight in the fraternity mill, but changes into a full size version instead.
M1911A1 (Custom)
The Gunsmith (Common) uses a Custom M1911A1 fitted with a red-dot sight and a compensator as his sidearm in the film.
When The Gunsmith shows his disloyalty to The Fraternity, he cocks the hammer on his .45 and instead of his M1911A1 being shown cocked, a Smith & Wesson 5906 is shown cocked instead.
Remington Rolling Block 1871 Cavalry (mock-up)
Seen among the weapons table when Wesley trains on the range is a Remington Rolling Block 1871 Cavalry pistol mocked up like a modern gun by adding a relex sight and attaching an AK magazine.
Ruger Super Redhawk
A Ruger Super Redhawk with a 9 1/2" barrel and scope is seen on the table of weaponry.
SIG-Sauer P226
An officer is seen approaching Cross' abandoned van after the car chase with a SIG-Sauer P226. Two SIG-Sauer P226R pistols, one K-kote, one Nickel, are seen on the weapons table. Wesley is seen using one during the mill shootout.
Smith & Wesson 5906
Wesley is briefly seen picking up two Smith & Wesson 5906 pistols during the shootout in the mill, although he never uses them. It is implied that he lost them when the stairs collapsed, and that he had picked up the two Baby Eagles before confronting the Butcher. However when the barrel is jammed, the handguns switch back to 5906's! One of the assassins in The Fraternity library is also armed with a 5906.
Also worth noting is the left hand shot isn't actually a left hand shot, it's reversed, as the ejection port is on the left side of the gun.
Smith & Wesson Model 64
Wesley picks up Smith & Wesson Model 64, the stainless counterpart of the Smith & Wesson Model 10 in the mill and uses it to kill The Repairman (Marc Warren) with a shot to the eye. He then jams the barrel of the gun through his head and fires an impossible twenty shots through his skull, using him as a "meat shield".
Smith & Wesson Schofield Model 3
The Repairman (Marc Warren) uses a Smith & Wesson Schofield Model 3 revolver as his weapon of choice in the film. the gun's ejector does not seem to work properly and the latch behind the sights seems to be broken since he is constantly having trouble closing the gun.
Star Ultrastar
When Wesley (James McAvoy) nearly falls from the derailed train, he is caught by Cross (Thomas Kretschmann). Shortly thereafter, he pulls a Star Ultrastar from his waistband and uses it. He is briefly seen using it during the mill shootout as well.
Taurus PT92AF
A stainless Taurus PT92 AF is used by Sloan to show Wesley that curving a bullet is possible.
Taurus Raging Bull
Fox draws and fires a Taurus Raging Bull at Cross during the car chase. A Raging Bull is seen on the weapons table. One of the assassin's in the library is also seen armed with a Taurus Raging Bull fitted with a red-dot sight.
Unknown Pistol
Two various assassin in The Fraternity library are seen with unknown long-slide handguns mocked up to look like a side-loader, one of which loads from the right, the other from the left.
This pistol is most definitively a sterling type 1 cut and modified with a top rail.
Wheellock Pistol (mock-up)
Cross keeps a pair of wheellock pistols mocked up to look like magazine fed guns. Wesley later takes both of these to the mill; one is lost while the stair collapse, and the other is shot out of his hand by Fox.
I think the magazine is gravity-fed. Notice how both Cross and Wesley try to fire the gun upside-down.
Shotguns
Sawed-Off Double Barrel Shotgun
Fox pulls a Sawed-Off Double Barreled Shotgun from under the seat of her car and fires it at Cross during the chase. The gun makes the typical "pump-action cocking" sound when drawn.
Benelli M3T
Two of the guards outside The Fraternity mill are armed with Benelli M3T shotguns, the shortened version of the Benelli M3 Super 90 shotgun.
Sub-machine Guns
Heckler & Koch UMP-9
Heckler & Koch UMPs are used by some of The Fraternity guards outside the textile mill and one in the mill during the final gunfight when Wesley grabs it from him for quick use. They are noted as the 9mm model based on their curved magazines.
Heckler & Koch MP7A1
Cross is seen trying to fire a Heckler & Koch MP7A1 with a reflex sight "pistol style", meaning stock retracted, fore grip folded like a handgun while chasing after Fox and Wesley in her car. Wesley is also seen briefly firing one in final battle, which strangely changed from a Heckler & Koch UMP-9. While in the movie it was only seen in a flashback in Cross's hand, in the trailers he is actually seen firing it.
Skorpion SA Vz 61
Fox draws a Skorpion SA Vz 61 submachine gun from her car to fire at Cross during the car chase.
Micro Uzi
A Micro Uzi is seen on the weapons table. One of the assassins in the mill is also seen using one.
Rifles
Armalite AR-180B
An assassin inside the mill is seen using the stock of his Armalite AR-180B to crush a rat.
Fantasy Sniper rifle
Cross (Thomas Kretschmann) uses a made up Rogue Assassin Sniper Rifle built from one of the flintlock/matchlock hybrids to kill Mr. X in the beginning of the film, using a telescope along with the rifle scope to aim at such an incredible distance. At the end of the film, Wesley uses the same rifle. To portray the flight path of the unique bullet, the bullet's path is rewinded until it reaches the rifle again.
FN FNC
A guard outside The Fraternity mill is seen firing an FN FNC at Wesley.
Heckler & Koch G3
A guard outside The Fraternity mill is armed with a Heckler & Koch G3 rifle, exact make uncertain.
Heckler & Koch G3/SG1
A guard fires a Heckler & Koch G3/SG1 rifle, as noted by the stock cheek rest. The rifle is missing its rear sight spindle and is not fitted with a scope. Guess the guy doesn't need to aim.
Heckler & Koch G36C
Seen farther back from the Benelli wielding assassin is another assassin with a Heckler & Koch G36C with the regular G36 carry handle.
M4A1
An M4A1 with an A.R.M.S. selective integrated rail system and scope is used by a sniper at the beginning of the film to kill Mr. X's secretary and to fire several shots at him before he flies out the window and kills him. I believe it could also very well be a Charles Daly Defense M4 with that rail setup.
Schuetzen Rifle
An flintlock German Schuetzen rifle, probably from the 18th century, is seen among Cross' weaponry.
Springfield 1861
A Springfield 1861 percussion rifle is seen among Cross' weaponry.