So this is a hit or miss. I strongly suggest for futher buyers that want to invest in silver rounds especially in large qty should invest in a scale. At least you can confirm what you have. Thanks again FishyOne for the links. There very helpful.
Well, on this particular auction it is clear that you are buying 8 troy oz. Seller says it is troy, along with the certificate. As was mentioned earlier, it was the Washington Mint that made the mistake of calling these items "one half pound". I don't think the seller is being deceptive here. And I don't think the Washington Mint was being deceptive...they just made a big mistake.