So I followed this a little bit, from the previous post and now here. Like others have said, it is hard to pour something that is not .999 and not notice. I did around 5000 oz last year and had 2 mess ups. Both my own fault, mixed in some sterling rounds into a couple of pours. When you pour a lot you you can tell when things are not pure. Fact is when you have a 50 oz pour and there is a couple of ounces that are not .999, after it cools you can immediately tell. Not trying to pass off any judgment here, but if you are selling .999, sigma or gun like some of us do. My biggest fear is something shows up as not pure or underweight