Locking up Powder

[mattiooo]

My son is getting to the age where I would like to lock up my powder. I have a Stack-On 8 gun cabinet that I'm going to use for the purpose. It doesn't have shelves (other than the small one at the top). This is the one: https://www.amazon.com/Stack-GCB-908.../dp/B002TOKR30

My current thought is to put the 1 pound powder bottles into ammo cans and be able to stack them on top of ammo in ammo cans, in the main section of the cabinet. I have about 7 one pound cans and might add one or two more (plus one 8 pound jug)

Question 1 - What is the optimal size ammo can for the powder bottles?

Question 2 - Is there a better idea than ammo cans for the powder? Either way, there will be ammo in cans at the bottom.