If you can find any Registered Skeet, Trap, or Sporting Clays even in your area, there will always be vendors present that sell reloading components. They often have a variety of sizes of shot- all in 25 lbs. bags. If they don't have them on site, they will give you their address and you can visit their stores or warehouses and buy it from there direct. I used to travel 60 miles to Bloomington, Illinois, with a friend, to stock up on shot and reloading components when I was actively shooting registered Trap. By buying in volume, we got a discount on what we would have had to pay elsewhere. Also, Skeet and Trap clubs often sell components. These are one fired hulls, plastic wads, primers, and shot, and you are only interested in the shot, but they are a good source. Ask around at sporting goods stores to locate the nearest club. Or contact the NRA.