With the 9mm jacketed bullets you aren't really suppose to crimp are you? I thought you are just suppose to take the flare off. One thing that I have noticed when I set my die to low, and it crimped, was when the press cammed over and popped at the end of the stroke. Kind of like when you are resizing. When seating the bullet you really shouldn't feel much pressure on your handle when just taking the flare edge off.
One thing that helps me is the L.E. Wilson 9mm gauge. I actually accidentally ordered the gauge, but it has came in handy. Every time I run some test loads I check a few throughout the batch.
Check it out