FBI Agents, Allcom guards, and Allcom henchmen have Glock 17s. Michael Jennings(Ben Affleck) later picks one up but it later changes to a Browning BDM.
M26 TASER stun pistol
When Jennings resists arrest, Agent Dodge(Joe Morton) incapacitates him with an M26 TASER.
Beretta 92FS Inox
When Allcom henchmen ambush Jennings at the station one of them whips out a Beretta 92FS Inox and shoot out a boys balloon before trying to kill Jennings. Note that the suppressor is crudely screwed on, as it is seen crooked in the closeup shots. This may cause damage to the firearm, the suppressor, and its user.
The Browning BDM is used by various henchmen and later by Jennings (Continuity error from a Glock 17)
SIG Sauer P229 Sport
Jennings manages to get a SIG P229 Sport away from a Henchmen and uses it briefly. He later drops the magazine from it and kicks it at an electrified rail to create a diversion to get away.
Two tone Beretta 92fs
Wolfe(Colm Feore) uses a Two tone Beretta 92fs for the duration of the film.
Kahr MK9
The Allcom lady Maya(Ivana Milicevic) who impersonates Rachel(Uma Thurman) pulls a Kahr MK9 on Jennings when he realizes she is an imposter.
Pachmayr Dominator
Wolfe(Colm Feore) tries to kill Jennings with a Pachmayr Dominator, a strange rifle caliber single shot conversion for the 1911 series, it is also fitted with a suppressor.
Glock 17L
The Glock 17L is utilized in the chase scene by an Allcom Henchman.
Beretta 92FS-C Compact
The Beretta 92FS-C is used by Allcom Henchmen and Wolfe.
Remington 870
The Remington 870 is seen in stowed in the front of a Seattle Police Department cruiser during the tunnel scene.
M16A2
The M16A2 is seen being wielded by an American Soldier with an M203 attachment when Jennings and Rachel look into the future and see the imprisonment of people.
M203
The M203 grenade launcher is seen mounted on an American soldier's M16A2.
CZ
Some kind of CZ handgun is used briefly by an Allcom Henchman.
Beretta 9000
The Beretta 9000S is seen briefly in the hands of an Allcom Henchman.
Ithaca 37
The Ithaca 37 shotgun is used by an Allcom Guard as he tries to kill Jennings before he is unrealistically(but cinematically) blown off his feet by shooting the floor.
Springfield Armory 1911 Custom
Rethrick(Aaron Eckhart) keeps a customized 1911 in his desk and uses it when he and his guards try to take on Jennings.
Well, I'm pretty sure that the rounds could cook off if a current were to be applied, probably destroying the magazine and sending shrapnel out, but the thing is that i don't know if Smokeless power can go off in that fashion.