The biggest problem with the Co-ax is the die lock rings you use. The die has to be perfectly perpendicular in the boss. If the threads in dies and lock rings have too much tolerance and the lock rings don't secure properly and squarely in the mating threads, the die will be canted and you'll not have straight ammo. I only use Forster or Lyman lock rings that can be clamped on the threads. I've had to flip those rings a couple of times to insure the die and rings are perfectly square. Too many issues with the rings that lock with a set screw.
It's nice to see someone who can articulate the much-vaunted "lock ring problem" with this press.
On the set screw type, have you tried raising the ram to put upwards pressure on the die before tightening the lock ring? That can be done with a case in the die of course.
