Adjusting The factory crimp die


I was having problems (especially in .40 S&W) with case bulge when seating and crimping in a single step.   It seemed like my sizer step wasn't working correctly, but when I checked the cases after the resize, the case looked allright?   I got a Lee Factory Crimp Die for the .40 S&W, set it up, backed off on the seat/crimp die, and all problems went away.   Now my .40 reloads will shoot in anybody's pistol.  
Sometime, when you think youre having sizer problems, its actually case bulge caused by the seat/crimp step.

You do need to keep track of your case length when using the FCD, since case length can control how much crimp is applied.   This is more often the problem in rifle cases.

In recent years the four basic jobs done by dies (deprime, resize, charge, seat) has had an addition, that is, the FCD (factory crimp die) should at least be considered in your sequence of dies/operations to perform especially for straight wall automatic pistol cartridges.   The factory crimp die is the last step in the loading process and resizes the cartridge a final time as it places a crimp on the case mouth to better hold the bullet.   I spot check cartridges using a Wilson case guage for the appropriate caliber to determine if my dies are set correctly, I also check OAL during a run, this way we don't get jams etc. at the range.   The factory crimp final resize compensates for the bulge that might have occurred when the bullet was seated.   The Lee FCD instructions are unclear so I have put up this page to clarify the FCD's adjustment.


FCD Adjustment

Unscrew the adjustment screw at the top of the die.   With no case in the shellholder and the ram at the top of it's stroke, screw the die in until it just touches the shellholder, then lock it down with the lockring.   Lower the ram, place a resized (not flared) case in the shellholder and run the ram to the top of it's stroke.   Now screw in the adjuster screw on top of the FCD until you feel it just touch the case mouth.   Lower the ram again and screw in the adjuster screw another half turn.   This should give you a moderate crimp.   After testing a few rounds you want more or less crimp, adjust the screw accordingly.   Remember, crimping can improve your consistency of velocity.   Be careful, don't overcrimp, it can cause headspace problems and possible misfires!



Readjust the Seater Die To Not Crimp

When I use a factory crimp die I don't allow the seater to crimp the case.   In order to not crimp with the seater die, unscrew the seater die body about one turn from it's normal setting (against the shellholder or plate), then readjust the seater plug in to set the proper OAL.   If you have a round of the correct OAL, back off the seater plug, place the round in the shellholder, run the ram to the top, then adjust the seater plug in until it just touches the bullet.   This should put you close to the right OAL, but you may want to tweak it a little.