Hadrian Semis?

It has been a long time since I played with fire and made castings of some of my coins (for a metals class I was attending and not for any nefarious purpose !) I seem to recall that copper did not cast well and alloy (bronze or brass) was the material of choice. Further the subject of 'shrinkage' was relevant to my project. Gold shrinks a smaller amount than silver (about 10%) and if memory serves bronze shrinks even more. Probably in the area of 15%. If the original flan were 28mm a cast copy might be around 25mm. The weight could go from close to 10 grams (or so) down to 8 grams. Add a bit of wear and you might be closer to 7.

Castings will always be somewhat 'light'. Which is why having a nice cheap digital pocket scale is sooo nice to have.