So I have some questions that I hope someone more experienced than I am can help me understand: 1. Is it normal for mints to produce bullion rounds that vary so much in weight and differ from published dimensions? 2. Is it possible to make a fake silver round that passes the magnetic slide and specific gravity but still fails the ping test (perhaps using an antifriction metal which has specific gravity of 9.3 to 10.6 and either tin or lead based would have diamagnetic properties)? 3. Are there any other tests I can do? Thanks for any help you can offer.