Cybergun is a rebrander. They don't make guns, but rather license guns with actual trades. So to answer your question about JP being Cybergun, the answer is no.
When I hear about a gun under the name Cybergun, I think a gun with trades. Not necessarily TM compatible, good, bad, or upgraded. JUST a gun with trades.
But depending on which CYbergun Famas you have, the answer is yes TM mags will work. The electric Famas takes TM mags, the spring Famas will not take TM mags.
Skip the formalities, it's Buster. The one, the only Buster
The man makes the gun, the gun doesn't make the man.
STOP SAYING I GOT X AMOUNT OF KILL WITH THIS GUN! It's a useless phrase. It comes down to skill
Newb = New player who hasn't had a chance to gain correct knowledge
Noob = Old player who's had a chance, but has yet to gain correct knowledge
People tend to base risk analysis more on stories than on data.