Ton of information in here, including lots of loads and different gun powders to use:
7mm Cartridge Guide within AccurateShooter.com
You don't provide any information on your rig or your location. you don't say whether you are running out of a short, medium, or long action. What length barrel? Are you long-throated to provide more case capacity or running shorter than 2.90" COAL?
From my personal experience with 26", 28", and 30+" barrels, if you are running a 24-26" tube (or running a sub-3.00" COAL), then you have very little chance of seeing 2,900 fps from a 7WSM running a Berger (or Sierra) 180, regardless of the load. I could not reach the 2,900 fps node on my 26" tube even with a heavy load; with the 168s yes, but not with the 180s; with my long-throated 28" tube (long action) I got to the 2,900 fps node. With my 31" long-throated F-class rig I got to the 3,000 fps node.
My personal favorite powders in my various 7WSMs for running Berger and Sierra 180s are RL-25 (but not in the desert - it was too temperature sensitive), H1000, H4831SC, (retumbo works also - but its not on my favorite list) IMR7828/7828SSC (if I don't have any of the H powders). A new powder to consider when they get some data out is the new IMR Enduron powders, and the new RL26.
Jeffvn