Hornady ELD-X in 7mm WSM

[AZ Wildcat]

I'm still fairly new to reloading - started about a year ago and so far I've only used published load data. I'd like to try working up my own loads for the new Hornady ELD-X bullets in 7mm WSM, both in 162 gr and 175 gr (which I'm not certain will stabilize well in my 9.5 twist barrel, but I'd like to try it out and know for sure). After talking with Hornady I plan on starting with reduced loads based upon their published load data for their older 162 and 175 grain bullets and work up from there, but I'm not sure what COAL to start at. For example, they publish a COAL of 2.850" for the 162 gr A-Max and 2.860" for the 175 gr Interlock, but will the longer ELD-X bullets be seated too deep at these COALs? I've got the OAL gauge so maybe I should determine the length-to-ogive where it touches the lands, back off .03" to .04" and start from there?

Any advice would be appreciated, maybe I'm over-thinking this.