You should be able to get an accurate, 3000 fps 180 grain bullet load using RL19, and work up to Alliant's max of 68.0 grains. Some folks have found good accuracy at 68.4 grains, but go there with caution.
If you have, or can get some Accurate Arms "Magpro," it is supposedly aimed at replacing the old WMR powder which Winchester took off the market. Winchester still uses WMR in their factory stuff, but you can't buy it. Initially, Winchester was recommending a charge of 73 grains of WMR with their 180 grian Nosler CT loads. That is not to say that 73 grains of AA Magpro would work great--AA's data shows a much larger max charge with Magpro...
Winchester replaced the WMR with WXR (X being for "extruded" powder they say). It comes out of Sweden (probably made by Bofors) and appears for all the world to be re-labeled RL22. Some folks like RL22 in the 300WSM. Nosler shows an accuracy load using their 180's and 67 grains of RL22. Alliant says 68 grains is max.
Here is AA's load data page for Magpro... it may be a bit slower than the old WMR, which would be good (better load density).
Accurate Powder data...
You should of course double check my data here, and proceed with caution.
Dan