Drop spawning guarantees that weapons spawning at set intervals in the map. Whereas normal spawning has it respawn after being picked up. So say you have the sniper on a 2 minute drop spawn, it'll respawn at 2, 4, 6, 8, 10 minutes throughtout the game no matter. Make sense?
just do exactly what you would think... have it drop from above the ground i usually just put down a door vertically, put the weapon on top of it in the orientation i want it, then just delete the door. when you start a new round, it should drop from the height it was at, which causes it to respawn like linubidix said EDIT: i think you also have to have the run-time maximum higher than the number placed on the map
I assume your question has been answered. If not let me know but for now, thread is now locked. Best of luck with your spawning.