Help with Cartridge cross sections

I want to display some cartridge cross sections in a shadow box or similar. I’ve had decent success cutting the bullets in half however if you have a quick and efficient way to do this I would like your input, what I need help with is replacing the powder. I’ve tried super glue, basically just covered the powder and it worked but it looks wet even after drying, I need a method where the powder remains looking dry and proper like the majority of those you see when doing google searches.

It won’t look dry but I’ve mixed it in clear epoxy and poured it back into the cut case. It makes for an nice display using the original power that won’t fall out.

I have mixed a small amount with epoxy and let it cure and its a really similar finish to the super glue. I think I may get some gel super glue and apply it over the dry glue and powder then sprinkle some powder on, hopfully this will give me a dryer looking result.