You might see if you can find some Herco. It meters horribly, but judging from the pics, a fluffy, bulky powder might be best, even for lighter loads, as there would appear to be a lot of space in the case. Most of the weight appears to be forward of the crimp groove, which gives you a lot of powder capacity over a typical SWC.
I'd be looking for a bulkier powder, personally.
