The Lee Factory Crimp die - how to use?


Matt Dillon
May 18, 2006, 10:16 AM
Folks, I have been using the Lee Factory crimp die as the final step in loading my .40 S&W loads. I recently got out the instruction page, and read it again. I'm not sure why this die has a seating stem (like the seating die has), because it appears to me that you adjust the die by screwing it in and out of the outer locking ring.
Can anyone clue me in as to how you use this die? Is it necessary to engage the seating stem, or am I missing something? Thanks so much in advance!

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May 18, 2006, 10:37 AM
here you go

for all other helps

May 18, 2006, 12:41 PM
Screw down die to shell plate for final sizing function. Stem is for the crimp. Use it like the stem on the seating die, screw it out to start and then screw it down gradually until you get the right crimp.

May 18, 2006, 01:29 PM
The crimp insert for pistols can be adjusted up or down with the stem. SO set the die as per instructions, and unscrew the seater 3-4 turns.

Insert a loaded round.

Screw the seater down.. at some point the crimp insert will make contact with the top of the cartridge.. that is your light crimp... give it maybe another half to full turn and look at your crimp. Adjust the seater in/out to increase or decrease the amount of crimp.

Typically you will see a shiney ring where the crimper has made contact... thats how I tell what kind of crimp I have.

Matt Dillon
May 18, 2006, 04:30 PM
Thanks so much, folks, with your help with this. I am going to start on a new batch of .40 S&W this evening, and this will help. Thanks again!

May 19, 2006, 08:57 AM
This was something I was wondering about a while back with 357 Sig and the Lee FCD. The question I've always had is what is the right amount of crimp? The instructions I've seen tell how to adjust the amount of crimp, but I've never seen anywhere which defines what 'right' is. :banghead:

Any thoughts? :)

May 19, 2006, 11:34 AM
I use the FCD to "fix" rounds that won't chamber in a max cartridge gauge. Admittedly, these arounds are the result of errors I made earlier. Anyhow, when I make an oversized round, I adjust the FCD in degrees until the round fits in the max cartridge gauge. That's how I arrive at "enough crimp."

May 19, 2006, 11:40 AM
I always measure a factory cartridge, and duplicate their crimp.

May 19, 2006, 11:49 AM
Right now I'm crimping enough to ensure the brass smoothly meets the bullet. My primary concern is set-back, but I've read that it's not as big an issue as it was once thought. I figure better safe than sorry and FCD my 357 Sig ammo. :)

May 19, 2006, 12:17 PM
The biggest problem I had when I started reloading was the meaning of the work "crimp".

To me, the "common-sense" meaning of the word crimp is that it is tighter than the rest of the case and holds the bullet in place, such as you see on a .357 or .44 bullet, what I now know to be called a roll crimp.

On 9mm, .40, .45, etc., we use the word crimp but it doesn't have the same meaning. On those rounds, the case is sized slightly small and the tension of the case around the bullet holds the bullet in place. The crimp is only intended to make the case wall perfectly straight, removing the belling you put in with you expander die, so that it will feed properly.

If you try to "crimp" one of those rounds, you will actually just end up resizing your bullet, making it loose in the case, and having the actual opposite effect of what you want.

As has been suggested, mike a factory round and see what the diameter is at the rim of the case and try going for that.

I have quit using the Lee FCD for 9mm, .40 and .45, my Hornady dies do a fine job with the taper crimp die as the last step and my press is a whole lot smoother to operate. I alway had quite a bit of drag from the FCD. The only real good reason to use the FCD that I see is as a final gauge to make sure the round will chamber in your gun, but I've never had a problem with that with my regular dies.

They work great on bullets with cannelures, I love it on my .223 rounds.

May 19, 2006, 02:36 PM
I'll mic a factory 357 Sig round and compare it to my reloads. Thanks for the info!

May 19, 2006, 02:40 PM
Lee factory crimp dies

First off, there are 3 distinct types of the FCD. For straight wall AUTO pistol rounds, they are a taper crimper. For straight walled revolver rounds, they are a roll crimper. Both of those have a carbide sizing ring in the bottom of the die, to iron out any lumps caused by crooked bullets or other faults.

The third type is for bottle necked rifle and auto pistol cases,(357 sig among others). It has a collet that is activated by the shell holder, it squeezes the end of the neck sideways into the cannelure. It is powerful enough to crimp into a bullet that has no cannelure.

They do NOT seat bullets! You must use the seater provided with your die set, making sure it is turned back far enough to NOT crimp. Most have provisions to crimp at the same time as seating the bullets.

I have FDCís in every handgun caliber I load for, also some of my rifle rounds as well. Iíve never had a failure to feed when using a fcd.

May 19, 2006, 03:02 PM
They do NOT seat bullets! You must use the seater provided with your die set, making sure it is turned back far enough to NOT crimp. Most have provisions to crimp at the same time as seating the bullets.Good info, Snuffy. If I remember correctly the Lee 357 Sig seating die does NOT crimp. I don't believe bottle necked cartridge dies do, either rifle or pistol.

I did my learning backwards; I started reloading 357 Sig, then added .308 Win. :p

May 19, 2006, 03:55 PM
I've always used it for my 1911 and .30 Carbine... since I don't trim the cases (straight walled cases).

Even for the .30-06 I still use it more for the post sizing.. as I have not had any issues with setback when feeding my Garand.

I also use the FCD when I make .30-06 blanks... again, for the post sizing. Seems to cure a lot of issues with blanks.

May 20, 2006, 03:38 PM
There appears to be a degree of confusion, and I've read it on other forums, about the function of the Lee FCD. It is what its name says, and is NOT a seating die. It must be used as part of a 4-die setup, whether or not the reloading press accommodates 4 stations, or the FCD is used as a separate final step. I agree that the Lee instructions are perhaps a bit terse, but when followed, they work. When used on a press like my Dillon 650, it's great, because it completely eliminates the step of gauging the finished ammo. When it comes to adjustment, the big thing to keep in mind is that you're using what amounts to a post-sizing die with a crimp mechanism. This means the adjustments have no relationship to those of the "standard" seat/crimp die found in most 3-die pistol sets. This is a different animal, and it needs to be viewed accordingly.

November 20, 2006, 10:12 PM
Resurecting an old topic because I just purchased a FCD for 9mm.

The video and the instructions on Lee's FAQ page don't jive. The video states run a cartridge with seated bullet up to adjust... the FAQ's state to do it with an empty cartridge.

From the LEE FAQ:

"The degree of crimp is adjusted by how far down the knob on the top of the die is turned in. The proper setting for this die is with the adjustment knob turned all the way up, turn the die into the press until it touches the shell plate or shell holder which should be in the raised position. Then, raise an empty case into the die and begin to turn the knob inward until you feel it stop on the top of the case. Another 1/2 turn will apply a good crimp and you can adjust from there to suit your specific need."

And again... the video:

So which is correct?

Thanks, West

Steve C
November 20, 2006, 11:55 PM
The video and the instructions on Lee's FAQ page don't jive. The video states run a cartridge with seated bullet up to adjust... the FAQ's state to do it with an empty cartridge.
......So which is correct?

Both methods work in setting up the die.

In the video the process is shown with the final crimp being applied to the loaded cartridge.

In the FAQ they give you the method of simply setting the die without further describing the crimping process of a loaded round.

November 21, 2006, 12:55 AM
Both methods work in setting up the die.


Ray P
December 3, 2006, 06:20 PM
The Lee FCD I have for 7.62x39 leaves three indents at the case mouth. The three indents cover most of the case mouth perimeter. I've seen the same indents on some Winchester 45-70 cases.

This looks to me like the FCD is deforming the case mouth, so I haven't reloaded any shells showing these marks.

But it sounds like people are reloading cases that have been through a FCD. Has anyone experienced problems with splits at the case mouth, or noticed that their cases are growing in length faster than normal?

December 3, 2006, 08:51 PM
I had a whole thread going a while back about loading 7.62x39 and using the Lee factory crimp die. It was the first time I had tried a FC die, and I started a thread due to the marks around the case mouth. You don't need a lot of pressure on the press lever when running the case up thru the FC die, just a little pressure really squeezes it good. I seat the bullet with the seater die to the correct spot in the cannelure, then run it up thru the FC die to squeeze it in place.

December 3, 2006, 09:15 PM
Put the FCD in the box, put the box on the shelf. It only covers up reloading problems and doesn't solve anything. It is a band-aid for bad rounds and a crutch for misadjusted dies. Sorry to be blunt, but I have tried them in 6 or 7 calibers (20+ different loads) and found no advantage to them at all. They can also increase the chances of setback, they destroy most loads with lead bullets, and they aren't needed. I read the hype, bought them, tested them, and came to my own conclusions. I was shooting well over 50K rounds a year when I used them, so it wasn't like I tested a box and gave up. I probably loaded 20K rounds between all of them I bought.

I kept 2, one in 45 Colt and one in 9mm. Both are used to load autoloader pistol bullets in revolver ammo. They will crimp a full cannelure in the autopistol bullets and prevent bullet jump. As far as I have found this is the sole place to use them.

Uncle Don
December 3, 2006, 09:25 PM
I would agree that they are not required but I do use them. The primary reson isn't what most people use them for however. If I use the seater/crimper to simply seat the bullet in my progressive and the fcd to put the crimp on, I can very easily change the seating/crimping die for a new style bullet by simply turning the ajustment knob. Since theere is no crimp and the fcd doesn't change, there is no actual die adjustment other than the adjustment knob and I've found this very handy.

I also definately use one for my 357 SIG as they do put a good crimp on an otherwise very short neck. Since I've used it, I've never had anything close to a setback problem.

December 3, 2006, 09:40 PM
The FCD is wonderful for 9mm and 45 ACP and takes all the mystery out of bullet seating and crimping these loads.

For .38 Special and .357 Mag I have tried all kinds of settings with Dillon dies and Lee dies and find the FCD once again solves any issues. I have zero rounds that won't chamber. With the Dillon dies in a Square Deal B I was always fiddling and ending up with several rounds out of every hundred loaded that were bulged. Cause of course was case length variation. But I'm not about to sit around and trim hundreds of handgun cases--so I use the FCD and shoot away with no problems. I would not load without them.

Of course, if you set the die improperly you can cause marking of the bullet. But that doesn't happen if you do it right. The instructions are very straightforward.

I have no experience with rifle loads and can't comment.

Steve C
December 4, 2006, 11:47 AM
I'm not sure why this die has a seating stem (like the seating die has), because it appears to me that you adjust the die by screwing it in and out of the outer locking ring.

What you are calling a seating stem is actually the part the crimps the case. It will not seat a bullet. To use the FC die screw it down just like you would a sizing die to just above the shell holder with the ram up. Back out the crimping stem, insert a loaded round and bring the ram up to top. Srew down the crimping stem to touch the case, back the case out and screw in the stem 1/2 a turn. Run the case back up into the die and you should feel it crimping. Screw in the crimp stem for more crimp, back it out for less.

The big advantage of the Lee FC dies for taper crimping semi auto pistol rounds is that you can not over crimp with it, IE reduce the case mouth to a size too small to headspace in the chamber. The Lee die will not reduce the case neck to less than SAAMI factory minimum and the final carbide sizing makes sure the case is no larger than Facotory maximum diameter.

Lee FC dies for straight wall pistol cases roll crimp and it may be possible to over crimp with these.

The Lee FC rifle dies use a collet to squeeze the end of the case into the canelure or against the bullet.

December 4, 2006, 01:40 PM
my FC die doesn't have any "stem" :confused:

when I look down thru my FC die, I see all the way thru it. There's a collet in there that squeezes the case when the case comes up.

Uncle Don
December 4, 2006, 02:10 PM
I didn't explain it very well. There are different type of factory crimp dies and I was referring to the one for straight walled handgun cases. It appears the one being discussed here is for bottleneck rifle. In any event, I tried to clear up the confusion on factory crimp dies on GT. Take a look if you like.

December 4, 2006, 10:37 PM
ok, I gotcha now. the only FC die I've ever used is the 7.62x39 rifle one. When I first tried it out, I was having some probs getting it right... and I didn't know anything about the "feel" and whatnot. But after getting used to it, it's a snap.

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