Sorry for the delay,
From base of case to nose,
First groove - 1.650"
Second groove 1.580"
This was simply a grab and seat. I grabbed up a new Starline case, and sized one of the 300's, then seated it until I got to the top edge of each groove. This is usually where I crimp at. Should at least give you a ball park length to work with.
Hope this helps.