I haven't bought any in years but last time it was as Mackys Gun shop. On the radio I have heard someone advertising BP down in Jacksonville. I'm not 100% but I think it was on the east side of town. Either Flatwoods outfitters or possibly Sportsmans lodge.
Maine Powder House is where I bought mine recently. Lady owner will tell you when her shipment is expected to arrive, if you call and ask. She is good to deal with.