"I would like to seat my bullets to that sweet spot, Is head space going to be an issue?"
Not sure I understand all you mention.
We all want to seat to that sweet spot, problem is in finding it!
Headspace is an issue only if (1) there isn't enough and we can't chamber the cartridges OR if (2) there is too much and we stretch cases a lot with each firing.
All "reloading" is done on fireformed brass. ???
