both.
List the calibre and manufacturer and the number of rounds you will be taking.
I list 10 flats of shotgun shells for each of the major manufacturers, plus 10 flats of reloads. They don't care how much you take....and you don't need to take it even if it's listed, but if it isn't listed, you can't take it.
My experience has been they just look at your paper work. No one has ever looked at my firearms.