Good to hear it and thanks for the update. RL22 eh? Might have to give it the college try in my 338 Edge. The low ES doesn't surprise me too much. The 338 Imperial / Edge cartridges seem to come by low ES and SD more readily than most other cartridges I've chronographed.
One thing's for certain. You've got the best brass possible with the RWS. That stuff is tough, tough, tough. It will take high pressures so don't go too overboard, which I've been known to do historically.
But not so much any more.