Re: 270 win load ?
I've been loading the 270 Win since the early 90's. Your advice so far it good. Any of these powders should work fine:
Re19, Re22 (and yes, these are made in Sweden and are temp sens.)
I do not read a lot about it anymore but one of my most favorite powders for the 270 for overall accuracy is AA3100, especially with a 140 grain bullet.
I tried magnum primers several times and did not notice a substantial difference in vel. or accuracy.
In my opinion, there are 3 ultimate powders for the 270: H4831SC, IMR 4831, and Re22. If you're looking for top vel. in your bbl, look to Re22.