The fictional EM-1 rifle (Electro Magnetic Pulse) which would actually be called EMP, is used several times through out the film. It is said to fire aluminum rounds at the speed of light, making it one of the only guns in movie history that actually could send someone flying when they are shot. The scope looks like a cam-corder with some type of green flashlight inside.
U.S. Marshall John Kruger (Arnold Schwarzenegger) steals a Desert Eagle off of another deputy during the plane shootout and keeps it until the zoo shootout when he runs out of bullets, conveniently having 2 bullets left(as opposed to the 40 or so he fires before without reloading) to shoot out the crocodile glass exhibit, and shoot an approaching crocodile remarking, "You're luggage."
Deputy Monroe (Danny Nucci) uses a Beretta 92FS as his personal sidearm for his duration in the film. Kruger uses one akimbo with his Glock 17 at one point in the film. A few unnamed thugs use 92FSs as well.
U.S. Marshal Robert Deguerin (James Caan) reveals his true colors by killing a woman with a dead assassin's Beretta 92SB, as noted by its briefly seen rounded trigger guard.
U.S. Marshall John Kruger (Arnold Schwarzenegger) uses a Glock 17 as his sidearm, swapping out the barrels from a regular Glock and the Glock 17 Pro barrel, threaded for a suppressor. He later steals one off of a man in the warehouse by the docks.
The Uzi is seen in the hands of several thugs throughout the film and is also used by U.S. Marshal Robert Deguerin (James Caan) and Johnny Casteleone (Robert Pastorelli).
Kruger tells Lee Cullen (Vanessa Williams) that he works alone and if anyone ever says they are with him, to use his Smith & Wesson Model 38 "Bodyguard", a snub nosed Smith and Wesson revolver with a rounded hammer shroud to prevent clothing snag. It appears to use Harret grips, as they wrap aroud the shroud.
Kruger uses a Benelli M3 Super 90 shotgun with a top-folding stock while in the dock warehouse. When two snipers armed with Railguns destroy half the place, the bolt on his gun melts to the reciever, rendering it useless. He tosses it over to a thug searching for him, and he picks it up. A sniper sees him with the shotgun and remarks, "Nice shotgun, asshole." and blasts him instead.
The men trying to kill Johnny and his wife during the beginning scene use older Walther PPKs. Kruger takes on of these for his own use, yet it changes into three guns, the suppressed PPK.....
Deguerin uses a Sawed-off Remington 870 to blast the vault code pad. It is doubtful a high security vault would simply open by blasting the code pad, to add.
The scarred thug uses a custom built Drillbit Launcher, that appears to launch a weighted rubber grenade which after several seconds, launches a 'Bouncing Betty' mine into the air. The mine explodes and propels hundreds of pieces of barbed darts in all directions. One dart succeeds in impaling Kruger's hand to the fridge door.
Sal (John Snyder) uses a Winchester Model 70 with a scope to shoot out one of the EM snipers. He fires a bullet right through the scope, similair to the legendary USMC sniper Carlos Hathcock, who did the same thing with the same rifle during Vietnam.
U.S. Marshalls towards the end of the film are armed mainly with M16A1s with A2 style handguards as evident by its A1 style sights and standard barrel.
