Criminal Minds

Glock 17

Derek Morgan carries a G17 w/ flashlight attachment. Spencer Reid carried one before switching to a revolver. JJ uses it. Most FBI agents carry glock pistols. This is somewhat unrealistic since the glock 22 is standard issue.

Springfield TRP

SSA Rossi carries a Springfield TRP throughout the series

Sig p226

Gideon carried one during the seasons he was in. This is a realistic wepaon since the FBI did issue the p226 after the 1076.

Smith Model 65 3'

Reid switches to one in season 4.

Beretta 92

Used by criminals and police.

Ar-15 variants

Swat teams from the FBI and several local police forces have m4 carbines. A milita 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 so he can attend to 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 vet sees milita with various aks, but it's in his mind, they are really swat officers with m4 carbines.

Remington 870

used by "road warrior" killer, fired from inside car. One is taken by a hitman and used to kill his daughter's captot.

MP5

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

various unknown pistols

Criminals in one used .22 automatics to kill innocents. Multiple revolvers are used, quite frequently over semiautos. Agent hotchner carries a small BUG in an ankle holster, a automatic. Possibly a g27, could not tell. Reid uses this weapon to kill a hostage taker. A milita leader carries a magnum, but stays holstered. He identifys it as a smith and wesson when commenting on agent morgan's glock

Unknown rifles: Can't quite remember what type of bolt action snipers rifles were used. One was used by a police marksman to shoot a person who was having Somalia flashbacks, another by a militaman to shoot a hostage taker.