The Beretta 92FS is the sidearm carried by Detective Charlie Crews (Damian Lewis) as well as Officer Bobby Stark (Brent Sexton) and other uniformed officers.
Glock 19
Det. Dani Reese (Sarah Shahi) carries a Glock 19 as her sidearm throughout Season 1.
Glock 17
Richard 'Rick' Larson (Jeffrey Pierce) is seen holding what appears to be a Glock 17 when confronting Dani in "Powerless" (S1E06).
Smith & Wesson 457
A Smith & Wesson 457 is found as a possible murder weapon in "What They Saw" (S1E04).
SIG-Sauer P220R
In "Civil War" (S1E07), Jeffrey Farmer (Trent Ford) aims a SIG-Sauer P220R during a standoff and moments before a SWAT sniper takes him down.
Revolvers
Smith & Wesson Model 15
While at the shooting range in "Tear Asunder" (S1E02), Charlie is seen firing what appears to be a Smith & Wesson Model 15 revolver, which had been his service gun before he was charged for life. In "Fill It Up" (S1E11), Detective Charlie Crews (Damian Lewis) discards his Beretta 92FS in favor of what appears to be the Smith & Wesson Model 15, when he searches for a perp on a revenge mission. This revolver appears to also have Pachmayr grips.
During a funeral for a slain police detectivem , the police Honor Guard are seen using bright nickel plated M1 Garand rifles to perform a rifle volley in "Farthingale" (S1E08).
Shotguns
Ithaca 37 "Stakeout"
In the pilot episode "Merit Badge" (S1E01), the drug dealer Lonnie Garth (Chad Lindberg) is armed with an Ithaca 37 "Stakeout"-style shotgun.