The Cabin in the Woods
The following weapons were used in the film The Cabin in the Woods:
Beretta Px4 Storm
The Beretta Px4 Storm is the standard issue sidearm of the guards at the facility. It is first seen in the hands of a guard (Patrick Sabongui - credited as "Elevator Guard") who is sent to kill Dana and Marty. Then Marty Mikalski (Fran Kranz) takes the Beretta and shoots a zombie with it. Later he hands it over to Dana Polk (Kristen Connolly). The Director (Sigourney Weaver) also tries to fire the pistol. One of the workers is seen committing suicide with a Px4. Daniel Truman (Brian White) also pulls out a Px4 when the creatures break in to the lab.
SG 552 Commando
Guards at the facility - only the Lead Guard (Phillip Mitchell) is credited - are seen with short-barrelled SG 552 Commando rifles with pronged flash hider and standard diopter sights. Some have attachments like a grip or ACOG (or both).
Heckler & Koch MP5K
Steve Hadley (Bradley Whitford) fires an MP5K when the creatures break in to the lab. It is not possible to identify the sub-variant, however the magazine release paddle can be seen for a brief second indicating that the gun is a genuine MP5K, not a converted SP89.