coal stove temps?

This is my first year with a coal stove.I have a efel coal/wood stove
Currently burning chestnut coal. What kind of temps can i expect the stove to hit? Currently with the flue dampner fully closed and the air intake wide open the stove is around 650 degrees.The temp of the flue gas just before it goes into my ss liner is 318 degrees. If coal ignites at 900 degrees shouldn't this coal stove be extremely hot with my current settings?

I run my Alaska Kast Console II, which burns rice coal, between 150 and 700 degrees.