According to the Lee Modern Reloading Second Edition, with a 154 grain bullet and H4350 powder in a 7mm WSM
Starting load: 54.0 grains-2775 fps
Maximum load: 57.7 grains-2920 fps at 62,600 PSI
I don't see in the manual a listing of whether they use a test barrel or an actual one, but I would imagine test.
According to the 5th Edition Sierra Manual, they don't list a 150 grain load with H4350, but they DO list it for their 160 grain bullet. They go all the way up to 3000 fps with 61.5 grains, and this was shot out of a 24" M70 with WLRM primers. This was also their pick for a hunting load.
As I'm sure you know...always back off from a max load before starting, but I am pretty sure you could even work up a bit hotter load than you already have and be alright.