I recently ordered some BP (Diamondback) from Jon Blackert of Crater Black Powder Blasting & Fireworks and was extremely pleased with his selelction, prices (even with shipping & Hazmat), and service.* His homepage & e-mail are addictedtoblackpowder.com and pyro247@hotmail.com or jonblackert@frontier.net
*I placed an order late last Saturday and it was at my door around noon on Thursday (May 5).