It's not as power weapon :pI'm 115 matches into the game and I still struggle with power weapon spawns. That's a great suggestion, though.
It's spawns on a regular rack. On Highpower it is often right up the stairs of the base on the rack next to the BR/Commando, if it's there you get a free Wasp defense spawn! Hardly anyone takes it, too.
(There is also one inside the base on Fragmentation on the wall that spawns very often, it's good vs vehicles in general).
There are places it spawns on other maps, but these are the most reliable I've found.