AHHMMM, If you don't know what you are talking about, it is best to keep quiet.
Beltfeds are legal in Kali, I know, a friend and I just both picked up a couple of 1919's. We can't link any ammo more that 10 rounds to comply with the 10 round limit on magazines (go figure). But if you have a few belts in our closet you bought before the the ban, then it is grandfathered in.
M2's (50 cals) are also legal (that is until the end of the year). It is a bad state for newbies just starting their collecting as they are resigned to m-14, m1a's, su-16 etc.
But for those of us that have been collecting for a while have plenty of grandfathered AKs, ARs, Galils, etc.
As for the Cali Barretts, I'd be interested in knowing if the swing magazine thingie would be reversable in case I ever leave Kali?
Got to ask Barrett, but then again, I've already had a few 50's, not sure I'd drop 7 grand on a rifle.