From The Stargate Omnipedia
X-699 plasma cannon
Plasma weapon of human engineering, similar design -- perhaps based on -- Dr. Jay Felger's plasma weapon
. The cannon is powered by a miniature naquadah generator
situated on top of the main housing. It is large enough that it must be held and fired in two hands.
Energy settings are not known, but the cannon is at least capable of stunning its targets, rendering them unconscious.
Bounty - Carter is forced to use the X-699 during an exhibit at Applied Technologies when a bounty hunter attempts to take her life.