I want to load for the .270WSM with Rl22 and/or Magpro. However, all I have is 210M primers. Cannot locate any 215's, cci 250, WRLM, or Rem's. Are these primers adequate?

i used mag primers in my 7 short mag.
i wouldn't hesitate to work up a load with the fed's in place of the wins.
especially if you are starting load development.
if you have a favorite load already back the load down a bit and come back up.
most of my target loads use federals, most of my cast loads use wins.
they are made from different compounds. but not enough brisance difference to worry too much about. just different ignition characteristics, and one will usually work just a bit better with your load.

mailmanmark ----- You are in luck, the Fed 210M primers will do just fine. They are all I use with my two .270 WSM's, when I go to anything else, I blow my groups. I have used them ever since I got my first WSM through hundreds of rounds, RL-22 and Magpro are my powders of choice along with RL-25. Good luck and good shooting.