I have no connection to this seller, except I bought two 1-lb cans of BP from him today. (Retail sources for real BP are a bit scarce in Illinois.)
Crater Black Powder, Blasting & Fireworks
P.O. Box 44
Mineral, IL 61344
He operates out of his house, located about 7 mi. north of Mineral, IL, on the west side of thle blacktop. His name is on the mailbox. (Mineral is located on U.S. 6, about 20 mi. west of Princeton, in Bureau County, north-central Illinois.) His prices are reasonable. You need to phone ahead to confirm when he will be there. He will ship, but with the usual silly restrictions on minimum amounts and hazardous shipping surcharge. Best to purchase in person. Of course, you need an Illinois FOID card.
In 1-lb cans, he has Diamondback, Schutzen, and Swiss powders. Some of Jon's customers have claimed that Diamondback, at $9.50 per lb, is a good powder and the best for the money. It is made in Brazil by Elephant.
Swiss sells for $18.50 per lb. Jon, himself, uses Swiss (for deer hunting) and hasn't personally tried Diamondback. I forget Schutzen's price, but it was more than Diamondback and less than Swiss. I bought one pound each of Diamondback and Swiss.
He has most all gradations - I bought FFFg for my replica revolver. He doesn't sell Pyrodex.
With my purchase, he gave me two ballpoint pens, two Diamondback stickers, and some candies. Such a deal. Should I put a Diamondback sticker on the rear bumper of my pickup? Maybe I'll wait until after I try it.