Hmmm its hard to say what's the best primary, like many people said, it depends on your strategy and the map your playing on.
My favorites are:
RPD with FMJ and Grip
bling pro(obviously)
hardline pro(if TDM) cold blooded if not
Last Stand(ROFL love pissing people off with this)
With secondary Rafica's red dot fmj(a must for last stand)
Martyr or Final Stand
I use that set up in scrap yard ,therminal and rust.
ACR with ACOG
Sleight of hand pro
Stopping power pro
Ninja Pro
Dunno I love the ACR with ACOG, great long range gun. I find that one on one close to medium range I get owned with the ACR due to lack of power, but at a distance the accuracy rocks.
Mainly use in Afghan.
Scar-H silencer
scavanger pro (120 rounds kicks ass)
cold-blooded or stopping power (because of the silencer)
Ninja Pro
Or
Tar with noobtube silencer
Thumper
Bling Pro
Danger close
Ninja Pro
I use either set- up for Karachi
And finally
M16 with Thermal and heartbeat
Bling Pro
Cold-blooded
Ninja Pro
For Wasteland or underpass.
RPD, ACR, and SCAR or TAR FTW.






and i like M39 raffica, and the spas. Also i keep a stinger in one of my loadouts for just in case 


