So you're full length resizing and your die is touching the shellholder and it still won't size it enough to chamber, I've ran into this once with a custom 270Wby. Other than getting different dies, what I did is take a shellholder in visegrips and use your benchgrinder to take a little off the top of it. This way you can size it just a little bit more and hopefully that'll do the trick. Do a little at a time and see if its enough. You can always take a little off the bottom of your sizing die, but shellholders are a lot cheaper!
