What reloading manuals do you have on hand?
What powders do you have in mind?
The Hornady manual has data for the 170gr FP in .30-30.
You'll be seating the bullets to the crimp groove (cannelure) so you can get a good crimp on them, but the manual lists 2.530" as the COAL.
Also, check Hodgdon's online data center.
http://data.hodgdon.com/cartridge_load.asp
They have data for the Sierra 170gr FP...which you can use for the Hornady 170gr FP too.
WW748 is my preferred powder for both 150gr and 170gr. I usually load 150gr though.