Tokarev pistol would be a great addition.. but it is a new round. Some guns that could be introduced to the game with existing calibers.
Maybe some IWI pistols like; the Masada, or Jericho series in 9mm and .45. HK pistols like HK45C, Or USP (9mm/.45). Or Walther p99 (adopted by the Iraqi army), Walther PP, maybe even CZ75 Or FN five seven pistol (5.7x28), HS200. Lastly the SIG P320.
If NWI and Focus Interactive would like to introduce a new caliber to the game, maybe they could introduce the bullet that changed history.
In 2012 during the Syrian conflict a cache of several thousand STG-44s used by both rebels and security forces. The round used is 8mm Kurz and it changed history because it was the first intermediate cartridge used in a large scale and it greatly improved the combat effectiveness of the German soldier.
The weapons lacking in some classes are the gunner and Marksman class
Security may benefit from the addition IWI Negev (5.56 or 7.62x51), m27 IAR
Insurgent forces could run RPK, RPD, RPKM, HK MG4
Security: Knights Armament SR-25 (7.62x51mm), French PGM Hécate II (.50cal bolt action), ORSIS T-5000 (7.62x51mm), M2010 Enhanced sniper weapon (M24 ((Upgrade from old rifles)) cosmetic purchase?)
Insurgents: Tabuk (7.62x39), Chukavin/SVC (7.62x54R), KSVK (12.7x108)
Both team’s Marksman: Iranian AM50
Uzi Pro, HK G36C
Rifleman, etc.: Steyr Aug (a1, a3) (multiple variants available for possible cosmetic dlc)
Uniform camouflage that may be implemented as part of the purchasable cosmetics or exclusive DLC for consoles:
black, or digital Chinese PLA Type 07 “arid” pattern, Kryptek patterns
The addition of Australian, just an idea