I don't care for hi-caps myself for many reasons, the rattling being my biggest issue. I prefer mid-caps which you can load to whatever your preference is.
As everyone already said you should be fine with hi-caps at most skirmishes and day games. It's generally only the 24hr milsim and more "hardcore" games that don't allow hi-caps.
I remember hearing/reading a few times it's possible to modify the Famas to accept stanag mags. This is probably your best option if you don't want to use hi-caps.
Searched real quick and came up with this: