In Day 4 of 24, former agent Jack Bauer, now working for the US Secretary of State, finds himself working again with CTU when a terrorist cell kidnaps the Secretary along with his daughter and a threat is made to launch a series of attacks on the United States.
The following weapons were used in Season 4 of 24:
Jack Bauer (Kiefer Sutherland) uses a Heckler & Koch USP Compact, chambered in 9x19mm Parabellum, throughout episodes 5-24
of Season 4, in both sound suppressed and unsuppressed form.
TRIVIA: There were only two H&K USP Compacts used by Kiefer Sutherland through the entire run of the series. This was because Kiefer is a method actor and did not like to change props. He only wore 3 real kevlar bullet proof vests through out all 8 seasons. (IMFDB thanks The Golden Closet for providing the documentation on this gun.)
SIG Pro SP 2009
Head of Field Ops Ronnie Lobell (Shawn Doyle) uses the SIG Pro SP 2009. After he is killed in episode 2. Jack Bauer (Kiefer Sutherland) uses this weapon when staging a robbery in episode 3, and when he rescues Secretary of Defense Heller (William Devane) (At the end of episode 5). Also used by Secretary of Defense Heller when covering Jack during the rescue operation in episode 6. Also used by Tony Almeida after he is brought into CTU.
In the beginning of episode 1, an assassin on a dirt bike derails a train and shoots a briefcase handler with a suppressed Beretta 92FS and takes his briefcase in episode 1. Abdul Manesh (Matt Gallini) uses a suppressed Beretta 92FS when killing all of Andrew Paiges (Lukas Haas) co-workers in episode 1. LAPD officers approach Richard Heller (Logan Marshall-Green) with their standard issue Beretta 92FS in episode 2. Several assassins use suppressed Beretta 92FS's during the ambush at Felsted Security in episode 7. Also some suppressed 92FS's are captured and used by Jack when he's low on ammo in episode 7.
Tony uses a Beretta 9000S to save Jack and Audrey at Felsted Security in episode 7.
Glock 17
The Glock 17 is seen by many CTU teams and terrorists. Navi Araz (Nestor Serrano) uses a sound suppressed 2nd Generation Glock 17 to hunt down his son and wife throughout episodes 8 and 10. Behrooz Araz (Jonathan Ahdout) gets a hold of the Glock 17 and kills his father in episode 10. Curtis Manning (Roger Cross) uses a 3rd Generation Glock 17 at his standard issue sidearm throughout the season. Habib Marwan (Arnold Vosloo) uses a 3rd Generation Glock 17 as his standard sidearm throughout the season. Also used by Tony when he arrives back at CTU after being held hostage by Mandy.
Glock 19
A CTU agent uses a Glock 19 at a dry cleaning store to capture Tomas Sherak (Faran Tahir) in episode 1. Jack Bauer (Kiefer Sutherland) also gets a Glock 19 after knocking out a CTU guard in episode 1. Omar (Tony Plana) also uses a Glock 19 when taking Audrey Raines (Kim Raver) hostage during Heller's rescue in episode 6. Tariq (Rene Millan) uses a suppressed Glock 19 to kill Behrooz Araz (Jonathan Ahdout) in episode 6.
Glock 20
Jack gets a Glock 20 from another dead officer and after making a call, he hands it to Audrey telling her to space out her shots and conserve ammunition in episode 7. A closer look at the barrel looks like a 10mm Glock 20. It's also surprising that Audrey keeps her eyes open the whole time with out blinking.
SIG-Sauer P228
A two-tone, suppressed SIG-Sauer P228 is used by a man in episode 14.
Smith & Wesson 4506
Secretary of Defense James Heller (William Devane) was supposed to be executed with a Smith & Wesson 4506 but was interrupted and saved by Jack Bauer doing a rescue operation in episode 6.
A Walther P99 is used by David Conlon when he attempts to kill Jack Bauer and Paul Raines. He succeeds in shooting Paul Raines in Episode 13 (7 p.m.-8p.m.).
Also used by Mandy in the final few episodes, most notably to kill Agent Castle.
Revolvers
Smith & Wesson Model 317
Dina Araz (Shohreh Aghdashloo) is seen giving a 3" stainless steel Smith & Wesson Model 317 to her son Behrooz Araz (Jonathan Ahdout) to clean up a loose end with his girlfriend Debbie Pendleton (Leighton Meester). The 617 is .22lr with an 8-round cylinder. The revolver is mainly seen in (S4E04) and (S4E05).
Submachine Guns
Heckler & Koch MP5A2
The Heckler & Koch MP5A2 is another weapon used by the CTU field ops team.
Heckler & Koch MP5A2's with Surefire 628 dedicated forend weaponlights can be seen in episode 7 at the CTU weapons center when Audrey and Jack are talking.
Heckler & Koch MP5K
One of the assassins uses a Heckler & Koch MP5K during the ambush at Felsted Security in episode 7.
IMI Uzi
During the kidnapping of Secretary of Defense James Heller (William Devane) two terrorist's with IMI Uzi's shoot several Secret Service agents trying to get Heller in episode 1. Several Uzi's are seen at Secretary Hellers Rescue by approximately 5 terrorist in episode 6.
Steyr SPP
A Steyr SPP (converted to automatic fire) was used in episode 1 by a kidnapper. A Steyr SPP is used in episode 6 by a terrorist at Secretary Heller holding location. One of the assassins uses a Steyr SPP during the ambush at Felsted Security in episode 7.
Sniper Rifles
Accuracy International AWP
Jack Bauer (Kiefer Sutherland) uses a Accuracy International AWP to kill two terrorists before they kill Andrew Paige (Lukas Haas) in episode 3. In episode 8, a sniper on a roof shoots Henry Powell (Robertson Dean) in the chest and all that is seen is a straight rifle barrel. It could have been a Heckler & Koch PSG-1 because of the straight smooth barrel but is very unlikely because of how rare this weapon is seen in movies, so I identified it as a Accuracy International AWP.
Rifles
AKMS
AKMS rifles are seen being wielded by terrorists in several of the opening episodes of Season 4. Secretary of Defense Heller (William Devane) takes an AKMS and kills 2 terrorists while trying to escape in "10:00am-11:00am" (S4E04). Jack takes one off a terrorist during the rescue of Heller in "12:00pm-1:00pm" (S4E06).
M4A1 Carbine
The M4A1 is seen used in Season 4 mainly by US Marines and CTU Tac team members. During the rescue of Secretary Heller, US Marines are seen armed with M4A1 Carbines fitted with foregrips, M68 reflex sights, AN/PEQ2A Laser Aiming Modules, and Tactical weaponlights in "12:00pm - 1:00pm" (S4E06). In "1:00am-2:00am" (S4E19), Chloe O'Brian (Mary Lynn Rajskub) uses the M4A1 to defend herself against one of Marwan's hitmen.
M16A4 Assault Rifle
Marines can be seen securing the area and shooting terrorist with M16A4 Rifle's in episode 6.
Shotguns
Mossberg 500
A Los Angeles Sheriff's Department Deputy uses a Mossberg 500 when responding to a hostage situation at the "Mercury Mart" in episode 4.
Other
M67 Hand Grenade
A US Marine is seen throwing an M67 hand grenade when clearing an entrance during the rescue of Secretary Heller in episode 6.
M26 Hand Grenade
A terrorist is seen tossing an M26 hand grenade in the direction of Heller and Jack during the rescue in episode 6.