LDP, your statement about pulled powder isn't correct as far as the companies I buy from. Each powder lot is from specific calibers of ammo. Artilliery powder is in another whole class, doesn't even make it into the sales that I buy from. I have bought hundreds of pounds of surplus powder over the years and as long as you use a reputable dealer, I see no problem with it. I do use multiple sources for my load data and work up each batch for performance and safety. One batch of powder I bought several years ago included data for several calibers that needed to be dropped by 20% to keep loads in the safe pressure range, but that is the only batch I have ever bought that was misrepresented, and that may have been due to improper storage at some point in its life before I got it. I have used some of the 20mm surplus powder for large capacity belted magnum loads, and if I could get nothing else, I wouldn't be afraid to use it, but it isn't the best choice. Most of the surplus powder I get today is from gibrass.com or patsreloading.com.
Just my 2 cents worth.. Blitzfike
Please let me explain, almost all military rifle, pistol, and machinegun ammunition is manufactured with 70% refurbished artillery powder, and 30% new manufacture. I did this on active duty, as well as civilian QC for military ammo. Any artillery powder lots found unserviciable for its intended purpose is refurbished if deemed still usable. This also includes other powders from other calibers. I'm not saying its unsafe, just be careful. Those guys selling it are in the business to make money. The process is to wet down the artillery powder with denatured alcohol regrind and reshape to the type caliber for use. Your sellers can tell you all they want, but its what it is.