you can do it 5 kills at a time. my suggestion is the EDZ Trostlands. there is a HVT that spanws inside a room. he brigs with him 4 Shanks that respawn quickly . the shanks are one shot kills.
it doesn’t have to be the same mag. kill 2 adds, reload, kill 2 adds, reload... etc. 👍🏻 also, when it comes to the “50 kills with smg while aireborne” you don’t have to be jumping... just stand on a wall/rock best place is EDZ around the church good luck