Criminal Minds

Glock 17

Derek Morgan carries a G17 w/ flashlight attachment. Spencer Reid carried one before switching to a revolver. Most FBI agents carry Glock pistols but is somewhat unrealistic since the Glock 22 is standard issue for the FBI.

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Springfield TRP

SSA Rossi carries a Springfield TRP throughout the series, this suggets he may have been HRT/SWAT trained to udse this weapon.

SIG P226

Gideon carried one during the seasons he was in. This is a realistic weapon since the FBI did issue the P226.

Smith & Wesson Model 65

Reid switches to one in season 4.

Beretta 92

Used by both criminals and police alike.

AR-15 variants

FBI SWAT teams and several local police forces have M4 carbines. A militia member uses a Colt Commando with a red dot attachment. A killer guns down 3 of his enemies with a fully automatic AR, possibly class 3 or illegally converted since it is described as privately owned. A shooter uses a scoped AR-15 from the trunk of a car, aiming to wound people but attend to the wounds as part of a hero complex (Reminiscent of D.C. sniper incident).

MAC-10

A bank robber uses a MAC-10, incorrectly calling it an Uzi.

M26 hand grenade

A milita member suicide bombs himself with one, killing a police officer.

AK variants

Members of a polygamist cult use AK variants in a shootout with a SWAT team. The leader fires an AKM in the air for attention later. A Somalia veteran sees militia with various AKs, but it's an illusion as they are SWAT officers with M4 Carbines.

Remington 870

Used by the "Road Warrior" killer; fired from inside his car. One is taken by a hitman and used to kill his daughter's captor.

MP5

Used by various SWAT teams, notably in the rescue at the polygamist compound. Equipped with suppressor.

Smith & Wesson Model 10

Reid's captor uses this pistol and later captured by Reid to kill his captor.