A safe starting load would be in the vicinity of 55 grains of RL 22. I believe you could safely work up from there, stopping when you find the most accurate load. RL 22 is at least as slow as IMR 4831 or Norma MRP, and I have seen loads as high as 60 grains (maybe hgher!!)of these two powders in the .270 with 130-grain bullets.