This can be done fairly easy when you spawn in as the Specalist, Angel, but it isn't made very clear in the game (I personally found anyway).
Press Left on D pad - this will bring some ammo bag thing out.
Press LT
Then press RT to assign a drop point.
This will bring down a loadout crate. There is a little cool down, but just do this 15 times and and can easily get this in a match of conquest!