Ty Curtis (Omari Hardwick) keeps a nickel plated M1911 pistol in a safe box, alongside a Beretta 92FS. He takes it out and uses it in the pilot episode after Lt. Shaw (Dylan McDermott) sends him back undercover. NOTE: The gun is not an M1911A1, but an M1911. Check out the M1911 pistol series page for info and differences on the forementioned guns.
Ty Curtis has a Beretta 92FS in a safe box alongside his M1911 in the pilot episode. The Beretta 92FS is also used by a guard and one of Warren Volk's men in the bank during the pilot episode. Dean Bendis (Logan Marshall-Green) also has a Beretta 92FS in a locked box along with his drugs and cash hidden under his floor boards.
Jaimie Allen (Nicki Aycox) carries a two-tone Glock 17 as his sidearm. She uses it in the pilot episode during the climax shootout. She also uses it in the gun range in the pilot. Also, a couple of criminals are seen with normal Glock 17s.
In the pilot episode, one of Warren Volk's bodyguards has an unknown snub-nosed revolver in an ankle holster. He tries to use it but is gunned down by one of Franzine's crew members.
Used by Ty to get an intruder out of his house in 2nd episode.
Rifles
M4A1
Most of Robert Franzine's (James Russo) men use M4A1 carbines in the pilot episode, including Dean Bendis. They most notably use them during the bank job, and the ensuing shootout.
One of the weapons that Carter used to stage a fake weapon transportation deal in the second to last episode.
Shotguns
Remington 870
Lieutenant Carter Shaw (Dylan McDermott) uses a Remington 870 shotgun with synthetic furniture, rear pistol grip and extended barrel in the pilot episode. One of Robert Franzine's (James Russo) men is seen loading a Remington 870 when they prepare for the bank job. In the 3rd episode "Purity", Dean uses one to bust a drug deal.