A quick word to the wise......when sizing with the 310 tool, always remember that the leverage you enjoy with your bench press isn't there. If sizing in the 310 is difficult, don't blame the tool. Try annealing the case necks/shoulders first.
I had a small batch of 6.5 Swedish brass that was giving me fits until I annealed the whole bunch. The force required for sizing went from intolerable to normal immediately.