Blakey Sims (Kwame Boateng) uses a Beretta Model 70 in "Cabrini-Green".
Beretta 92FS Inox
A Beretta 92FS Inox is seen in "Black Hand and the Shotgun Man". Hugh Killian (Patrick St. Esprit) is seen with the pistol in "Bathhouse & Hinky Dink".
Flintlock Pistol
A Flintlock Pistol is seen on a display case in "Gillis, Chase & Babyface".
Glock 17
The Glock 17 is used by the Chicago Police Department as their sidearm.
Glock 19
Superintendent Colvin carries a Glock 19 as her sidearm.
SIG-Sauer P226
The SIG-Sauer P226 is seen with some CPD officers. A stainless version is seen in "The Gold Coin Kid" with a suspect when he was able to get it from behind his pants and fire it inside an unmarked CPD Ford Crown Victoria.
SIG-Sauer P226R
The SIG-Sauer P226R is seen with some CPD officers.
Vektor CP1
During the car chase at the beginning of "Pilot", Luis Esperanza (Remy Ortiz) uses a Vektor CP1 as his sidearm.
Walther PPK
In "Cabrini-Green", Gibbons (Delroy Lindo) uses a Walther PPK to defend himself. It has pearl grips installed.
Revolvers
Smith & Wesson Model 10
A Smith & Wesson Model 10 is seen in "Gillis, Chase & Babyface" with an East Asian storeowner.
Smith & Wesson Model 36
A Smith & Wesson Model 36 was found on Johnny Pavich (Andrzej Krukowski) when it gets confiscated by Evers and Wysocki in "Wild Onions". It was referred to as a "38 Special".
Unknown Revolver
In the background, a Chicago PD officer had a revolver.
Submachine Guns
Heckler & Koch MP5A3
In "Black Hand and the Shotgun Man", the Heckler & Koch MP5A3 was seen in the hands of a Latino gang member.
Heckler & Koch MP5K
In "Gillis, Chase & Babyface", a bank robber is seen with a Heckler & Koch MP5K.
Ingram MAC-10
An Ingram MAC-10 with no stock was thrown away by a criminal during a foot chase in "Wild Onions".
Assault Rifles
Colt Model 933
The Colt Model 933 is sometimes seen with the CPD during armed raids.
Colt M4A1
A Colt M4A1 is seen in "Pilot" in a gunrunner's hideout.
Sniper Rifles
Valmet M78/83
In "Black Hand and the Shotgun Man", a Valmet M78/83 with a scope and a SVD Dragunov-style stock was seen in the hands of a Latino gang member covering his boss Daniel Romero.
Others
Pistol/Revolver frame
Trivia
Chicago Police Firearm selection
Unlike other major city police departments, all Chicago Police officers must buy their own duty gear. This includes a uniform, sidearm, handcuffs, light, baton, etc. Each officer receives an annual uniform allowance of $1,800 to do so.
The sidearm must meet the following requirements:
Be manufactured by Beretta, Glock, Ruger, Sig Sauer, Smith & Wesson, or Springfield Armory.
Be chambered in 9mm, .40 S&W, or .45 ACP.
Be Double-Action Only, Hammer or Striker-Fired.
Officers who were in the department before 1996 may keep their old DA/SA or SAO pistols, as well as their Smith and Wesson or Ruger revolvers in .38 Special. Recruits normally choose Springfield Armory, Smith and Wesson, or Glock pistols. They must be chambered in 9 mm until the recruit's 18-month probationary period is over.