I've been where your at with a 270WSM and the die is likely not the problem, it's your head spacing or your chamber is a little fat. If a WSM is head spaced long and you run it hot enough your expanding the case out in the area of the web and just forward. In order to size that portion of the case down to fit you end up setting your shoulder way back to get it into the die enough to size down the back of the case.
At first my solution was to grind the die, worked like a charm but hind sight I would have ground the shell holder, both are anti accuracy ways of doing it unless you grind it perfectly concentric, because when your die and shell holder contact at cam over you want things square.
I then was getting good cases but I was moving a lot of brass and I knew that wasn't going to work in the long run so I started looking things over, I put some Prussian blue on the shoulder to see just when I was touching it and I found out that I was moving it back like .009-.010 to get the rear of the case sized, WOW that will screw up all kinds of things!!!!
I ordered a head space gauge and started measuring stuff and found my head space was the same as I was having to set the shoulder back, way to long! So being a Savage I whipped of the nut and re-set the head space to the go gauge then took the gauge and set up a new Redding S FL die to it so it matched what I had just set for head space on the rifle. Fired some stout loads and tried it again, I had to set my die down just a little more for spring back but when everything was set the handle just cams over and the die and shell holder are in good contact. I re checked when I was contacting my shoulder in the die and found just as it cams over I set the shoulder back just a tad.
I have a custom 270 WSM reamer setting here so I slid it in to see just how large the chamber is also, lets just say I didn't need a dial indicator, but I will live with that for now!!
Now my brass is moving about .003 per firing after resizing instead of the .010, and now that I'm moving way less brass my bullet run out has gone from a solid .006 to .002 or less. Neck tension is staying even and my SD has gone way down and long range hit predictability has gone way up!!!
I have concluded that a custom barrel with a well installed chamber set to the correct head space is priceless!!!
Long explanation I know but man I learned a lot with this rifle and WSM brass.