I did about similar a couple years ago - thought that I was buying a bag of previously fired Weatherby brand 7mm Weatherby Magnum cases - was like 25 or so loaded rounds mixed in there. Did not even bother to ask seller - if he thought he was selling brass cases, not likely he would know much that was useful to me about the loaded rounds. I pulled the bullets - found 3 different weights - I believe they were Hornady brand - the Round Nose ones were identifiable before I pulled them, but I could not tell difference between 140 grain and 160 grain Spire points, until they were pulled. Might have made perfect sense to whomever did those up. I dumped out the powder - for sure two different colours - not the same to each other. Then pressed out the primers because I had no clue what they were. And found that three of those loaded cases had head stamp "270 Weatherby Magnum" - even though they were loaded with 7mm bullets. I burned off the powder and the primers. Was surprise to me about the primers - had soaked close to a year in 0W20 motor oil - and all went "pop" when I lit them with a propane torch - I had assumed they would be dead, but they were not. I never tried to fire any with impact, though - just playing the torch flame on them