FN P90 Personal Defense Weapon

"This is a weapon of war. It's meant to kill the enemy."

- Jack O'Neill

The P90 submachine gun is the standard submachine gun for SG-1 since the mission to P3X-888, as well as the standard issue weapon for the Atlantis expedition.

Overview
It was selected as a standard issue weapon, because it had better armor-penetrating and killing power than the 9mm Heckler & Koch MP5 it replaced. Like other firearms, it is technologically primitive compared to Goa'uld, Wraith, and Ori weapons, but it is more than capable of piercing the armor worn by Jaffa, Ori soldiers, and Wraith warriors. According to Jack O'Neill, it is a weapon of war, designed to kill the enemy, and holds better offensive capabilities than the staff weapon, which he said was designed primarily to intimidate.

The SGC uses the P90 USG variant, which has two RIS (Rail Interface System) mounting rails on each side of a reflex (red-dot) sight. There is also P90TR (Triple Rail) variant with no sights, only three RIS mounts. They're used for mounting accessories, such as a Kull disruptor or flashlights (which are commonly shown on nearly every weapon). SG version also features a laser pointer serially mounted in fore-grip (P90 LV/LIR). Within the SGC and Atlantis, they are typically either black or olive green, although a gold variation was also in use around two years after the destruction of the Ori.

History
Although the P90 has been standard SGC issue since 2000, Daniel Jackson and Teal'c have only begun using the weapon in recent years. .