I try to stay at least one presidential election ahead. I keep a small stash of self defense rounds, but since I primarily target shoot and constantly try new loading ideas, I don't stock much assembled rounds-- I make them up before each shooting trip after I decide what 'experiment' I want to try for that trip. I keep a spreadsheet that totals my inventory of bullets, lead, primers and powder, and tells me when I'm running short of anything. Every time I do a loading session I click the appropriate spot in the spreadsheet for what I am loading, which bullet, which primer, and how many grains of which powder. That way the inventory always stays up to date. My spreadsheet also does a little calculation for each firearm based on what I have in stock and tells me what date I expect to run out for that firearm-- and if that date is not one presidential election ahead I buy whatever I need.