Two full-length M16A2 rifles are seen in Santa's armory and are later used by Santa and Mrs. Claus in the promo for the proposed television special The Night the Reindeer Died.
A M60 machine gun can be seen in Santa's armory and is used by two of the elves.
GE M134 Minigun
Lee Majors (playing himself) uses a hand-held M134 Minigun with a M60 handguard in the promo for The Night the Reindeer Died. This is the same Minigun that had previously been used in Predator, and it appears in the same configuration as that film, before the weapon was modified slightly (with a new forward carry handle and the M60 handguard removed) for its appearance in Terminator 2: Judgment Day.
Submachine Gun
Heckler & Koch MP5K
The terrorists who attack Santa's workshop in The Night the Reindeer Died carry Heckler & Koch MP5K submachine guns, which can be identified only in one brief shot where the silhouette of one is visible.
Shotguns
Sawed-Off Double Barreled Shotgun
During Frank Cross' overly-effective trailer for the Scrooge TV special, a man can be seen committing a drive-by shooting with a sawed-off double-barreled shotgun.
12 Gauge Double Barreled Shotgun
Eliot Loudermilk (Bobcat Goldthwait) barges into Cross' office with a double-barreled shotgun near the end of the movie. Notably, he fires three shots between when he enters Cross' office and when he first reloads.
Revolvers
Smith & Wesson Model 60
Frank Cross (Bill Murray) keeps a S&W Model 60 with pearl grips in his desk, which he uses to try and kill the ghost of Lew Hayward (John Forsythe).