I used LRM S&B this summer in my 300wm without issues. They seem to be not as hot as the CCI and WLRM. I ran into some issues with hang fires in subfreezing weather this winter with slower powders (RL26 & H100). I did not have problems with CCI that day but I only shot them in loads with H1000 if I remember right. I have a pretty good number of LR and LRM S&B primers on hand but doubt I will use them after the temperature related problems I experienced.
Not withstanding the above, I had read on line where a bench rest shooter obtained very good ES with S&B LR primers, which is what had prompted me to try them out.