Using 58.5gr Retumbo under a 115gr Berger in my 6mm-06 AI for 3265fps in a 26" Mullerworks 4R. I know three other guys who have all settled on the same load in their rifles.
Given the nominally larger bore size in the 25-06 AI, it is likely a great starting point for 115gr loads in formed brass to work up from using a chronograph.
