Yes, DC does have laws about possession of ammunition components and it is the same as having loaded ammunition and is illegal to possess unless you have a firearm registered in that caliber.Does DC have any laws regarding reloading your own brass?
Apologies for throwing all these questions your way Novus, I'm out of country right now so this is a big help for me.
So if you have a gun registered in .223, then you can own the powder, bullets, brass and reload.
And no need to apologize, I like keeping sharp on DC gun laws and the practice is good.