User blog comment:DiegoAnime3000/The Manga adaptation is here!/@comment-25086632-20151117190820/@comment-25086632-20151117223156

In the trailer the only time we see her change magazines is when she switches over to the black cross one when she switches to war-scythe mode.

In the manga she doesn't switch to war-scythe mode until after the panel where we see the Dust round.

Idk though. There're some...inconsistencies in the manga (lack of a black cross on the second magazine when she switches, Ruby not wearing her cloak with her uniform).

So while I guess they could have normal bullets, and almost certainly did at some point, it's currently my opinion most bullets have a Dust core.

We'll probably either have to wait for more manga to come out to clarify, or for another Q&A that allows for longer questions like the Facebook one.