John Rahway (Paul Walker) carries a custom two-tone Colt Officer's ACP with Novak-style sights, flared magwell, slanted slide serrations, skeletonized hammer and trigger, and ambidextrous safety, throughout the whole film. He most notably uses it during the hotel room shootout.
SIG Pro SP2022
The SIG Pro SP2022 is the sidearm of choice for A.J. (Hayden Christensen). He is most notably seen using it during the hotel room shootout.
The Glock 21 is the main sidearm of Gordon Cozier (Idris Elba) throughout the film. IMFDB previously mis-identified this pistol as a Glock 17, but screencap evidence (shown below) indicates that Cozier's Glock is almost certainly a G21 (it may also be the Glock 20, which has the same type of thicker grip, but the G21 is more common).
Glock 17
Jessie Attica's (Chris Brown) sidearm in the film is a 2nd Generation Glock 17 with a stainless steel slide.
Detective Eddie Hatcher (Jay Hernandez) carries a standard black Glock 17, as does a Russian gangster during the hotel room shootout.
Glock 19
Dalonte "Ghost" Rivers (T.I.) uses a Glock 19 as his sidearm in the film. After being released from prison, he locates the Glock and a wad of cash in a safe box.
Beretta 92FS
Detective Jack Welles (Matt Dillon) uses a Beretta 92FS as his sidearm throughout the film, as do almost all of the LAPD officers in the film. A.J. is also seen briefly wielding one during the bank robbery, when he's posing as security. The armored car guards also use Beretta 92FSs in the film (even though John Rahway mistakenly identifies their sidearms as Glocks while the crew is casing the target). A Russian gangster also carries a Beretta 92FS during the hotel room shootout.
Smith & Wesson 4506-1
Sergei (Gideon Emery), a Russian gangster is seen pulling a Smith & Wesson 4506-1 when Ghost comes to visit him. Another 4506 is seen in the hands of a guy who tries to rip A.J. off. One is also seen in the hands of a Russian gangster during the hotel room shootout.
M1911A1
Jack Welles (Matt Dillon) and Eddie Hatcher chase a criminal, who pulls out a nickel-plated M1911A1. He tries to shoot Welles with it, but is shot by Eddie 'Hatch' Hatcher (Jay Hernandez) before he gets a chance.
SIG-Sauer P226
When Jack Welles (Matt Dillon) is looking at photographs of weapons and explosives confiscated from the Russians, a reverse two-tone SIG-Sauer P226 is visible in one of the pictures. This is the same P226 that was used originally in 2 Fast 2 Furious (ironically, Paul Walker starred in both movies).
Rifles
M4A1 Carbine
M4A1 Carbines are used by most of the main characters, John Rahway (Paul Walker), Gordon Cozier (Idris Elba), Jake Attica (Michael Ealy) and Jesse Attica (Chris Brown) during the bank robbery. The gang also uses M4A1s during the armored car robbery. When Jack Welles (Matt Dillon) and his squad raid a Russian mafia crew's hideout, they find more M4A1s.
Accuracy International AW-F
John Rahway (Paul Walker) assembles an Accuracy International AW-F on a rooftop during the armored car heist. His plan was to use it on Ghost (T.I.), if he decided to run. Note: this specific AW-F that Paul Walker uses in the film, it's a Texas imported AW-F.
AKM
A gangster is seen firing an AKM during the hotel room shootout.
Shotguns
Remington 870
When Dalonte "Ghost" Rivers goes to see his Russian 'friends', one of them pulls a pistol-gripped Remington 870 with synthetic furniture. The particular gun looks like a folding stock model, with the stock removed and black furniture.
Mossberg 500 Cruiser
A Russian gangster is seen using a Mossberg 500 Cruiser during the hotel room shootout. Jake (Michael Ealy) manages to kill him and take his shotgun. Jake's brother Jessie (Chris Brown) also equips himself with a Cruiser at the bar.
Mitchell High Standard
Sergei (Gideon Emery), the lead Russian gangster is armed with a Mitchell High Standard shotgun with a sawed-off stock, and in true Hollywood fashion, he manages to fire more shots than the mag tube can hold without reloading.
Mossberg 590 series
Jake Attica (Michael Ealy) uses a Mossberg 590 with an extended magazine tube and ghost ring sights after the hotel room shootout at the bar. An armored car guard is also seen armed with a Mossberg 590 with an extended mag tube and without ghost ring sights, when the gang is planning their next heist.