I just went on ADI and Hodgdon sites to see if they still show the same data for 308 Win. Under 168gr bullets the Hodgdon site shows subsonic data with Titegroup and Clays. Has anyone else found other data for subsonic loads on the Hodgdon site? It is not on the ADI site(makes most of Hodgdon's powder).

Have you tried their trailboss formula?

Trail Boss http://www.hodgdon.com/PDF/Trail-Boss-data.pdf 150 gr is a little fast, go to a more heavy bullet to slow it down, maybe?

I haven't crono'd the rounds yet but in a bolt action, sixteen inch barrel with suppressor:
308 Winchester 180gr Hornady bullet
12gr Trailboss - supersonic crack
10gr Trailboss - very quiet