A Beretta 92F is seen in the hand of the deceased Deputy Paul Henderson (Larry Odien) when the sisters find him at the sheriff's substation. They find the expended shell casings but not the actual slugs, which were shot into Henderson's killer. The absence of his attacker's blood (to say nothing of the bizarre condition of Henderson's corpse) is one of the early mysteries of the film. The Beretta 92F also is carried by Deputy Steve Shanning (Nicky Katt) and is used by Sheriff Bryce Hammond (Ben Affleck) near the climax.
Dr. Jennifer Pailey (Joanna Going), after finding the dead Deputy Henderson, smashes open the sheriff's gun cabinet and appropriates a Mossberg 500 shotgun. Her sister, Lisa (Rose McGowan) rightly points out that a gun didn't do Henderson any good, but Jennifer insists on taking one "For whatever." She proves incapable of loading it properly, despite claiming to "understand the concept," leaving Lisa, who was raised in L.A., to load it for her.
Ithaca 37
When Jennifer smashes open the gun cabinet in the sheriff's station there are two Ithaca 37 shotguns seen. Bryce, Lisa and Stu are seen with the shotgun at various times in the film.
The military personnel at the checkpoint outside of Snowfield, Colorado all carry MGC M16 replica rifles that are fitted with M16A2 foregrips and "birdcage" flash hiders to make them look like M16A2s. MGC M16s fitted with replica M203 grenade launchers are also carried by some of the Biological Warfare Unit soldiers, and are also seen in the armory of the unit's transport vehicle.
Ruger AC556 Muzzelite Bullpup
Ruger AC556 assault rifles fitted with Muzzelite Bullpup stocks, laser sights, forward vertical grips, and night-vision scopes are carried by the Biological Warfare Unit soldiers in MOPP suits who accompany the science team into Snowfield. The Rugers used in Phantoms are the same rifles that were originally built for the movie Tank Girl, though they are fitted with different accessories in this film; they were also later re-used in several episodes of Firefly.
Other
Defense Technologies 1315 37mm
Def Tech 1315 37mm launchers are used by Sheriff Bryce Hammond (Ben Affleck) and Dr. Jennifer Pailey (Joanna Going) to fire the bacteria canisters into the shape-changer.
M203 Grenade Launcher
Several of the Biological Warfare soldiers carry MGC M16 replica rifles fitted with M203 grenade launchers. Four more of these replica rifle/grenade launcher combinations are also seen in the armory for the transport vehicle when Sheriff Hammond retrieves the DefTech launchers.