A friend of mine sent me a link to Handloading Supply in Surprise AZ that has a lot of powder and primers in stock at great prices.
Here:
https://handloadingsupply.com/
Various discussions on the web recommend extreme caution as they may be scams.
Their physical "location" in Surprise AZ looks like a residence. The FFL # listed is issued to MAC ARMS LLC at that address.
Return merchandise has to be sent to Garden City KS.
The big clue is payment has to be made via Venmo or Zelle. I think you might be able to pay via a credit card but then, they have your CC # and you have to get a new card.
Just a heads up.