FFFFg Powder

[Justice]

A great deal depends on where you are.
However, go here for Goex's distributor list. Flinters are kind of unusual so you're probably looking at ordering it. Lotta government interference involved.
http://www.goexpowder.com/distributors.html

[bat119]

I used to make my own use a wood dowel on a piece of glass to crush small amounts ffg or what ever into flour for priming, there is a small chance of ignition so go slow and do small bits a time. I found this was the best for preventing hang fires.