I don't know about "most", but yes anyway.
IME, a 400 is more or less the same as a 550. In 300 Blackout, 357 Magnum/327 Federal revolvers, I would use the 400’s and 550's interchangeably (but not for my higher pressure 223AI or Grendel's).
In my one 223AI, I want a hard cup as my loads tend...