I doubt that you'll see +/- .005 if your dies are properly setup and locked down. The 40 is a taper crimp and as long as you make sure you get it right, setback shouldn't be an issue.

Setback is really more an issue with a round that's chambered repeatedly, like the top round in a carry weapon that's loaded and unloaded every day.

The test for your crimp is to try pushing the bullet in with your thumb or against the bench. Play with a dummy round would be my suggestion.

Get the correct COL for the exact bullet your using, stay away from max loads until you master the taper crimp and you should be fine.

__________________
Just Say No - To Social Media