When do we get Lv.120-140 Dual Bowguns? (Von Leon, PVP & Cygnus)

All 140 weapons are out, dropped by Empress Cygnus. However, the reason some of us already have 140 weps is because of Music Box event, but those did NOT give out Kataras, Dual Bowguns or Hand Cannons. The boss has never been defeated in GMS so that's why you have not seen any of those. The hot time event will give them out though, but only like a total of 1 of each weapon all across the servers.

 Spoiler

Dropped only by Cygnus (Jumbo Primary Ribbon), pretty much confirmation that it has been killed.

But yeah, they are in-game. Whether or not anyone has them is another story.