Nick,
I just a take quick look at the speed and feed info you will find in link below and use past experience.
http://www.machsupport.com/forum/index.php?action=dlattach;topic=20045.0;attach=28531------------------------------------------------------------------------------------------------
FWIW ........................
There are a number of calculators out there and I am sure they all do a mathematical great job.
Cleveland was leader back in the old days and actualy published their works.
The only real testing over time, and that was for machining different types of steel, was done by SME ( Society of Manufacturing Engineers)
and provided factors to be taken into take account when calculating. I have noticed that some / many of the insert manufactures use what SME published.
Out of curiousity I went through a whole bunch of calculations to see what values one should use and will just say that it realy becomes "subjective" since there is no hard guidance on the assumptions one could use when calculating. We designers / engineers tend to be conservative in approach.
So what I elude to is to use any advanced calculator as a guide with consideration taken into account for your systems / tooling capabilities.
In the end nothing beats some basic testing especialy for different materials.
Foot in mouth and off to the side,
RICH