The Sentinel is a 2006 thriller starring Michael Douglas as Pete Garrison, a veteran US Secret Service Agent who goes on the run when he's accused of being involved in a plot to assassinate the President. Kiefer Sutherland co-stars as the agent who heads up the task force assigned to find him.
The following guns were used in the movie The Sentinel
An M4A1 carbine can be briefly seen in the hands of a Secret Service Counter Assault Team (CAT) Operator in the initial scenes. Note: USSS CAT transitioned from the Colt M4 to the Knight's Armament Company SR-16 Carbine in the early 2000s.
A Remington 700 PSS can be briefly seen in the hands of a Secret Service agent after Garrison's escape, and in the hands of a Secret Service Counter-Sniper on the roof of the building in Toronto.
SIG-Sauer P228 9mm pistols are used by all the actors portraying US Secret Service agents, including Agents Pete Garrison (Michael Douglas), David Breckinridge (Kiefer Sutherland) and Jill Marin (Eva Longoria). When one of their agents is found dead, Breckinridge notices that the safety on the agent's SIG is still on, meaning that the agent wasn't ready to fire (since Secret Service agents are trained to draw and flick off the safety in one motion). Note: The standard sidearm of the United States Secret Service is the SIG-Sauer P229 chambered for .357 SIG rounds. The Secret Service did use the SIG-Sauer P228 sometime between the late 1980s and early 1990s, after switching from the .357 Smith & Wesson 66-2 revolver. However, since the movie takes place in 2006, the Service had already adopted the .357 SIG P229 by then. As a technical aside, neither the P228 or P229 have an external safety to be disengaged before firing.