Stargate: Atlantis

FN P90

This is the standard sub-machine gun of the Atlantis expedition and is carried by most Marines and armed scientists. It wouldn't be a Stargate show without this overused weapon.

Beretta M9

The standard U.S army sidearm and also widely issued to both military and civilian personal on Atlantis.

Kimber made 1911 Unknown model

Major (later Lieutenant Colonel) Sheppered carries one of these in preference to the standard-issue Berettas. On closer look, it appears to be more of the 1911s made by Kimber.

FN Minima (M249 Squad Automatic Weapon)

Used by the Atlantis expedition, most notably in the Season 2 episode Duet where several are used to shoot down a Wraith Dart.

M2 Browning .50 Caliber

Several of these can be seen mounted on pintle mounts being used as anti-aircraft weapons in the Season 1 episode The Siege: Part 2.

Colt M 4 Carbine

One of these, equiped with an Aimpont sight, is carried briefly by Lieutenant Colonel Sheppered in the episode Runner, and is also picked up by Doctor Carson Beckett in the same episdoe, but is never used.

H&K G36K

Seen used by a few characters and notably in one episode by Teal'c and Ronon.

Wraith Stunner Rifle

Used by Wraith to stun their prey, allowing them to feed on the helpless but still-alive victims. several are captured and used by the Atlantis expedition, most notably by lieutenant Aiden Ford in the two-episode arc The Storm/The Eye.

Ronon's pistol

Ronon uses what looked like a heavily dressed up revolver. In the story it fires like a phaser, stun and kill with an extra option to blow a huge hole into things. Apparently in the story, the color of the gun changes according to whichever setting. A Redish orange for kill or "blow a nasty hole in the wall" and White for stun. There is also ammo for this weapon since in scenes where scenes of Ronon reloading his weapon

This image shows on closer inspect, it is possible Ronon's gun might be a heavily dressed up Single Action Colt or Ruger

Genii pistol - Dressed up Beretta M92

In the episode showing the people known as the Genii uses pistols that looked like dressed up Beretta M92s.

Winchester Model 1894 Lever Action dressed up as a futuristic Gun

These, along with the Beretta M92SFs that have a huge sci-fi shroud on them, are guns from the movie TIMECOP, with Jean Claude Van Damme. This is Model 1894 lever action rifle with three fake shotgun barrels on them (and to date, I don't think I've ever seen them fired in either a movie or TV show).

Dressed up double barrel shotgun