An expended 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. Deputy Steve Shanning (Nicky Katt) also uses one, as does 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.
M16A1 assault rifles fitted with M16A2-style hand guards are carried by the military personnel at the checkpoint outside of Snowfield, Colorado.
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 soldiers in MOPP suits who accompany the science team into Snowfield.
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.