NDC of 40 for 10 parts is really high. This could mean 2 things:
1. There is a distinc part to part variation during your MSA, or
2. You are actually using a gage more precise than what is needed for the measuring process.
If part to part variation is not that high, then NDC of 40 could only mean your measuring devide is very good.
Let's wait from others for other conlusions. I'm sure somebody there could give a deeper insight.