Hey all,

Can you guys recommend the best way to determine how to adjust a taper crimp die in a Hornady LnL AP Press for the right amount of crimp on 9mm?

You should probably read your die directions. I assume you would screw the die in or out until proper crimp is set.

on my lnl, using lee factory crimp, i run the ram all the way up, hold down the level with my knee, REMOVE the locking ring from the lee (as it is too short) and screw it down until it touches the shell plate .. then back off the ram, and turn in another 2/3 of a turn or so...

The way I did it, was take a factory loaded 9mm that already has the crimp, adjust the die down on that cartridge, load up a clip full.

I then let one chamber, took it out to see if loading from the clip caused the bullet to be pushed back (it didn't).

Then shot the clip and looked at the last bullet after it cahmbered to see if the bullet was pushed back, it wasn't so good to go.

I usually adjust the die so that it reduces the diameter at the very end of the case about .002" more than the diameter say .1" below that point, if that makes sense. You want to remove any belling done for bullet seating then add just enough to get no setback. I have never had problems with setback in the 9mm so I don't taper it much.
C.G.B.