ORIGINAL: cayugad
Depends on the State the gun shows are held in. They too are held to some strict regulations not only by State regulation, but local regulations and fire code. I have found powder in gun shows. A better place to look is watch for rendezvous in your area. They often have stands where they sell lots of things. There you can get black powder, but again.. being a seller's market at many of these places you pay a premium price. The best way to get your black powder is order it in large amounts at one time. Also, checksome shooting clubs. Often they order powder by the case, you meet new friends, and have a place to shoot.
Yes the rendezvous are the way to go. I have a friend who is in a reenactment group who said to save my 1 lb cans since he and some friends buy 50 lbs and he will sell me 5 lbs for $10/lb. I just bought 2 lbs retail for $18.95/lb, Goex in 1 lb can. I only shoot the BP in my FL, but I go thru about alb a year now. Chap Gleason