Well, huh.
I was nosing around StarLine's site and it occurred to me, they do not make any sort of belted brass. I "need" some .458 Mag brass both for the .458 and to form into .416 Taylor as both of those coffee cans are pretty light. It makes some bit of sense as they are largely dedicated to rimmed and rimless cases and I expect adding belted into the mix involves very different tooling than what's on hand.
I will note that what's in stock is amazing compared to recent years. If you have been waiting on something, now would be a good time to check and possibly order!