How do I get the M249

I set myself to automatic rifleman and my weapon to M249, but when I enter a server I'm not given that weapon as an option - though see others using them.
Do I have to complete the offline challenges to make this happen? Is it a function of in-game rank?
Any help appreciated, and thanks to all who enter harms way that others will be safe.
Headquarters Headquarters Battery, Second Battalion, Third Field Artillery... MOVE!
Do I have to complete the offline challenges to make this happen? Is it a function of in-game rank?
Any help appreciated, and thanks to all who enter harms way that others will be safe.
Headquarters Headquarters Battery, Second Battalion, Third Field Artillery... MOVE!
Comments
Rifleman (M4, M16 red dot, shotgun, SCAR red dot),
Automatic Rifleman (M249),
Marksman(M16 acog, M14 acog, SCAR acog)
Sniper (M24 scoped, M14 scoped)
If the Role is full, other players have already grabbed that weapon.
However, there are no unlockable guns. You can use any one you want if you get it quick enough!
This has been a test of the emergency flame-fest system. Please do not adjust your set.
Thank you very much. It had me flumoxed.