I have a few duiten by now from the periods 1500s till mid 1700s. (from the Netherlands myself) One thing i learned finding these is that they are very susceptible to wear and tare unless you have it in prestine condition (very rare).
A few reasons that has influence on their size and weight:
- When found in a field, on farmlands, or near water. The copper is very sensitive to moist and manure. Especially the manure used on fields degrades the coin quickly.
- Back in the days they were made, people tended to chip off small amounts of coins (clipping) and use the metal to melt it into ingots even copper. A VERY risky practice. It was seen and treated as forgery and was severely punished, even by death.
- just plain ware by use.
- The amount of copper used by the minter and the (accidental) loss of copper during the hammering process)
You rarely find 2 of the same coins with matching weights, sizes.
The measurements you give aren't as way off as you think and it could be that the measurements you compare it too is from a coin with ware and tare. So no it is not wierd and yes you have a normal sized coin.
