I have always believed that the best tactic is to stock up on powder, primers, brass and either projectiles or the lead to make your own along with an assortment of dies for all the types of ammunition you use. Then keep your powder and primers stored in airtight containers with lots of desiccant. I can churn out a lot of cartridges in a fairly short period of time. If you have the components you can make the types you need at the time instead of doing a lot of guess work about your future requirements.
AND, the brass is reusable!! I wholeheartedly agree, brother!