The M16 is the primary weapon of SWAT and seen used by all the members in the series including Sgt. Dan "Hondo" Harrelson (Steve Forrest), Sgt. Deacon "Deke" McKay (Rod Perry), Officer Jim Street (Robert Urich), Officer Dominic Luca (Mark Shera), and Officer T.J. McCabe (James Coleman).
Armalite AR-18
SWAT trainees are seen practicing with this rifle in the first episode. It's also used by the assassin in the episode "Bravo Enigma", as well as being identified by name in the same episode.
Colt Official Police
The Colt Official Police is used by several characters throughout the series, notably uniformed officers.
Colt Python
Walther P38
M1 Carbine
Winchester 1897
Ithaca 37
Remington 700
The Remington 700 is the primary weapon of SWAT's designated sniper, Officer T.J. McCabe (James Coleman).