The CZN-M22 is the standard issue weapon for Section 9. Firing 5.7mm rounds it looks alot like the French FA-MAS with the exception that the top can be popped off to reveal the inside(you can see this many times when Kusanagi does it). This gun can be modified with a 'B-Kit' to use Hypervelocity 'Hot' Loads without screwing up (although like any gun that fires HypVel Rounds, it will overheat under sustained fire; see the end of the movie for an example of this). It can also be fitted with a single shot 50mm grenade launcher(this isn't seen in the movie which sucks because it would look REALLY cool).
CARTRIDGE: 5.7x28mm
OPERATION: Blowback
RATE OF FIRE: 800rpm Cyclic
SIGHTS: Adjustable
FEED: 35 round removable box magazine
OVERALL LENGTH: @65cm*
WEIGHT (EMPTY): 2.6kgs*
WEIGHT (LOADED): 3kgs w/ 35 rounds*
*: This does not include the attachable Grenade Launcher.