Explosives license and certified magazine.
If your friend is thinking of going into the business he needs to query the local authorities on the subject and get definitive answers, not internet conjecture. CA has some stupid laws concerning ammunition, better check up on it because I think it will be a problem. Anywhere in THE USA, which is now something like 12 states, no license to sell ammunition or components as long as you aren't the one producing them. Reloading tools are no different than screwdrivers or wrenches.