An objective Lee FCD vs seat/crimp comparison

[mistermog]

I have a 9mm Lee 4 die deluxe set that I've been chasing leading issues down with and decided to perform an engineering style (read OCD) test.

Disclaimer: The expander in the powder die is not the stock 9mm set spud, I purchased the .38 S&W expander which is .001 or .002 wider I believe as per the Jailer sticky because the case wasn't being expanded enough originally and squishing them down too. All boolits were Lee 120gr TCs, weighing about 125gr and seated to 1.07 as precise as I could.

I did a .3565 crimped with the FCD, a .3565 crimped with seater die, .3575 crimped with the FCD and a .3575 crimped with the seater die just to see how they all came out. All rounds were measured at the base 3 times in the same area on all 3 boolits.

The 2 I set with the seater did not push back at all with 3 chamberings
the ones with the FCD both set back .0045

The .3575 seater die didnt go into battery the first time but i pushed the slide and closed it so it swaged down to the chamber size. (Smith n Wesson M&P, tight chamber I knew this would happen, anything over .357 drags a bit)

I then pulled all 4 and measured them.

.3565 FCD was now .355
.3565 seater was now .3565

.3575 FCD was now .356
.3575 seater was now .357 (possibly because of the assisted chambering?)

All 4 were winchester brass (I read they might be the thickest?)

Also of note, the 2 with the FCD took 1-2 hits with the kinetic puller to pop out, the 2 with the seater die crimp took 4-5. Those left a healthy groove in the bullet that measured .353, the ones with the FCD left a faint line that was it. (No idea if this is too much crimp, never tried this before)

So, at least in my case I found out the FCD rounds were smooshing my bullets a tad and still not crimping very tightly as I had it setup, which in a .356 bore was just enough to be slightly smallish.

Yep, I know there are a LOT of variables in this test but I think for me it solidified that with bigger than jacketed, I shouldn't use the FCD and should set it up as a 3 die set. I just found it interesting to see numbers and results first hand and thought someone else might find this useful or interest or at least confide that I'm not the only one this obsessed with thousandths of an inch.

And yes, all this data made me giggly. [smilie=p:

[MasS&W]

Ladies and gentlemen, mistermog is the most OCD reloader I know, but he's alright :P

[trying2learn]

I don't remember where I read this but I remember reading with a lead boolits not to use the fcd from any manufacture. I have found that I don't need any of the crimp from that die they all just work great with the standard seating die. Unless I have a freak round like last night where. The brass flared a hair to much. I used the crimp die to keep from having to redo the entire round. Put just enough crimp to keep the boolits from moving.

Sent from my SPH-L710 using Tapatalk 2

[mistermog]

While I do think I might have a -tad- too much crimp set right now, before with the FCD set loose it was still squishing bullets. What Ive now seen is that bullets bigger than the jacketed sizes could be squished.

I use the FCD with .3565-.357 bullets in .357 and .452 in my 45acp loads and those don't get squished at all.

[popper]

Use the expander and then the FCD. Crimp is to prevent setback, not neck tension

[Gohon]

I think what you experienced was the carbide ring in the FCD was swaging down the bullet and brass before being crimped. The brass would have some spring back where as the bullet would not, thus you were losing neck tension. The crimp on the FCD bullet was probable just as solid as the seater die but that bullet and brass were not swaged down. That would also explain why it took less effort to pull the FCD crimped bullet and the indention in the bullet was less than the seater die..

[MikeS]

Ok, as was already said, the carbide sizing ring in the FCD sized down both boolit & case, then case sprung back, but boolit didn't, so no neck tension. This is why the boolits from the FCD swaged down.

I have another test for you to try. load the rounds as you did before, but this time set the seating die to not crimp at all, at most start to remove the bell in the case. After you're done, either remove or loosen the boolit seating spud from the seating die, and adjust the die body down some to slightly crimp the brass. Run the cases thru the seating die once again, this time it should crimp the case without touching the boolit. Now check and see how these cartridges measure out. With auto pistol cartridges that need crimping (actual crimping, not just removing the bell) if you try to do the crimp & seat in one operation the boolit is still moving forward, so it scrapes some lead off the boolit, and these scrapings accumulate right in front of the case mouth. Cases that headspace on the face of the cartridge (such as 45ACP, or 38Super, or most other rimless pistol cartridges) will start having trouble fully chambering due to this lead buildup. The answer is to seat in one step, and then now that the boolit isn't moving relative to the case, you can crimp the boolit in place without scraping lead.

What I do for 9mm is buy a standard crimping die (not the FCD, just a Taper Crimp die) I got mine from Lee as it was less then $12.00 IIRC. A 'standard' taper crimp die has no moving parts other than the lock ring. For revolver cartridges that need a roll crimp I simply buy an extra seating die, then remove the seating stem and use it as a dedicated crimping die.

Keep in mind that there are 2 different crimping dies sold by Lee as 'Factory Crimp Dies' one is their Carbide FCD, it's the die that causes so much trouble for boolit casters. The other is their rifle type FCD also called a collet FCD, and if they make one in a caliber you're reloading for, get it, they really work great, and there's no chance of them sizing down your boolit when using it.

[357shooter]

I don't remember where I read this but I remember reading with a lead boolits not to use the fcd from any manufacture. ...

The Lee FCD is unique in that it has a sizing ring as part of the die. That's what is swages the bullets down, when using cast instead of jacketed. Other manufacturers do not have this design and don't have the problem. Others also don't call theirs FCD, which is the name of the product from Lee. FYI

[captaint]

Actually, mistermog - I think we NEED to be concerned with thousanths of inches in this business. One thou, especially with 9mm, will cause leading if it's a thou too little. Seems like splitting hairs, but we really NEED to do just that - sometimes. enjoy Mike I think your experiment was very interesting and revealing. Good work.

[mistermog]

Yes Mike, when I had it adjusted to crimp too much it would shave lead until I backed it up a touch.

I know what the FCD does and why people say it does them, but I never tried something like this myself. I wanted to prove it with my own eyes and figured people might find this interesting.

[captaint]

Actually mistermog - I think we NEED to be concerned over thousanths of inches. Especially with the 9mm - a thou too little and you can get leading from that alone. Sometimes, that
.001 will make all the difference. Success/failure. enjoy Mike

[fredj338]

Use the expander and then the FCD. Crimp is to prevent setback, not neck tension

Just not true w/ a taper crimp. You can NOT prevent setback taper crimping. It's all about proper neck tension, always has been. Get that right, the crimp is just finishing the round. You can actually over crimp & buckle the case enough to cause loss of neck tension.
I had to find out myself so bought a LFCD for my 45acp. It only makes accuracy worse w/ all bullet types. So why? Set your dies up properly, the LFCD is a solution looking or a problem.

[popper]

You can NOT prevent setback taper crimping Guess we'll have to agree to disagree on that one. Yes, you can buckle the case, yes it may 'dent' the CB, so will FCD. Yes, it is more difficult on CB without crimp groove. Yes, most of us use it to just remove the bell. Yes, set your die properly. Don't make incorrect global statements. TC is really a mild and controlled roll crimp.

[MtGun44]

Lee pistol FCD is useless.

If you have normal dies, set up properly, it provides NOTHING useful and the
possibility of damaging the boolit.

A "solution" looking for a problem.

Bill

[prs]

Lee pistol FCD is useless.

If you have normal dies, set up properly, it provides NOTHING useful and the
possibility of damaging the boolit.

A "solution" looking for a problem.

Bill

I have no use for the damned things given how they were intended to be used. But they do have two uses I have found "off label". One as a "bulge buster" even if the cases are not bulged. My Carbide Factory Cr ap die sizes the cases slightly less (ie the cases remain slightly larger) than do the corresponding full length size dies. This larger diameter still leaves some need for the expansion dies, but brass is being worked less. Then you can salvage the crimp ring from the die and place that in a powder through die body that you are not currently using, that is, from another calaiber set. In a progressive press, that allows seating and crimping in seperate stages without buying another die. Then again, if you do not have a Carbide Factory Cr ap die, then don't buy it. If you have one, don't toss it ir de-ring it, you can get some use out of it on the sly.

prs

[HangFireW8]

All 4 were winchester brass (I read they might be the thickest?)


That has not been my experience.

However when comparing decades and decades of production against decades and decades of othery manufacturer's production, anything is possible.

That is why I measure. I have a dial caliper, a vernier ball micrometer, a 1/10K edge micrometer, and they are all calibrated and agree with each other.

So, whenever I have a question like this, I measure.

Do you have any other brand brass to measure and compare against?

HF

[mistermog]

I have a harbor freight caliper, it only agrees with itself when the battery is clean. :)

[MikeS]

prs, I use a Lyman Multi Expand Charging die, basically an M die, but with the expanding spud hollow like Lee's expanders, so I never use the Lee expander die, so I took the crimper out of an FCD and put it into the expander die body (along with the adjuster) to make an adjustable crimping die. I then put a bulge buster kit on the remaining FCD body, so now if I get cases that are bulged (range pickup) I can run them thru the bulge buster. So I now have 2 usable dies, rather than 2 I don't use. I used to use the crimping die quite a bit, but I've since gotten a Hornady taper crimp die, and I use that more often these days. And to not work the brass too much I resize 45ACP brass with a carbide sizing die from 45Colt, when doing this I never get shells with a waist like I did when using the 45ACP sizing die.

[chutesnreloads]

Well I found it interesting.Thanks

[mistermog]

:) thanks

[noylj]

An Engineering test would be based on "Design of Experiments" and not "OCD Today."
I found my eyes crossing trying to read the initial post, so I will post my own answer to the title--
The Lee FCD for straightwall cases produces the best crimp of any other crimp die I have tried. It is right with Redding taper crimp die in terms of accuracy of ammunition produced.
I have been reloading for 40 years and in all that time, I have never needed to measure a crimp. I imagine all the old-timers simply look at the crimp against a white background and feel the crimp with their fingers to be sure it is "good enough."
Since I started reading about people actually measuring crimps, I have tried it myself.
Here are my findings:
If the crimp is sufficient that your eyeball shows no remaining flare and your finger doesn't feel any "catch" going from the bullet to the case, the flare is as good as it needs. Then, you pull a bullet and make sure there is no mark on the bullet. This gives me a small "range" for my measurements. I have found that if I can see or feel the flare, the rounds will not be the most accurate. If I can pull five bullets and find more than a very slight mark on no more than one or two bullets, the crimp is too much and accuracy will be hurt.
If I use the Lee FCD or Redding taper crimp die, I will generally shave about 0.2-0.5" off the average group at 25 yards. Once the die is adjusted, it is NEVER adjusted again for that cartridge.

[mistermog]

While my initial post might have been a bit wonky to read, the main point was that the FCD does reduce bullet diameter if it is bigger than the .355-.356 of jacketed bullets (ie oversized lead ones).

As far as the crimp, that was me not knowing how much to seat the die as I have never done that before.

The OCD mention was because my friends are tired of hearing about me talking about thousandths of an inch because they dont pay attention to that level of detail. :)

[Frozone]

Here is the problem in your data:
"
.3565 FCD was now .355


.3575 FCD was now .356
"
The carbide ring didn't get smaller or bigger. If it was the carbide ring swaging things down then you would see ALL the after diameters be the small size, not just reduce .0015 under what ever was crimped. This leads to think the problem is in the adjustment on the crimp not the carbide.

[mistermog]

That part confused me a bit too actually... however that was measured at the base of the boolit, not the crimped part.

Also it was barely crimped, it barely took any effortvwith the puller to pop it out.

[357shooter]

Depending upon the alloy there could be more springback on the fatter bullet. It looks like the measurements were taken with calipers, which round. So the difference in size is likely not that large.

[Springfield]

Winchester brass is some of the thinnest, which is why I need to use it in my Ubertis in 44-40. The Uberti cylinders are cut a bit small, and only Win. brass will work with my .429 bullets. Starline is almost as thin, CBC is teh very thickest. Same goes for all the 45 colt brass I have measured.

[Tazman1602]

OK maybe someone can help me out here. With the exception of. 45acp for which I use a Dillon taper crimp die I use Lee's FCD on almost all of my cast bullet loads and *some* of my jacketed loads.

I get exceptional accuracy from all of my big bore rifles...444....458...etc using the FCD and my cast bullets.

I also shoot a LOT of. 38 special and. 357 Magnum handguns and I do use a light FCD crimp to avoid setbacks. All of my cast bullets are sized to the slugged barrel and I just can't envision how a small crimp, at the mouth of the case, can resize the entire bullet --- please set me straight on what my little mind can't comprehend guys.

I know if you overcrimp you can really screw things up but have had such good luck with the FCD as opposed to using the built-in crimp on the seater dies I'm having a tough time understanding.

Art

[mistermog]

In the past, Ive had the FCD on my oversized 9mm adjust to about 5/8ths-3/4ths of a turn past the case mouth point to give slightly more than the instructions say and I either still got set back or it mangled the boolit.

If its working for you and you arent getting leading or any problems, sit back and enjoy it. :)

[mistermog]

Depending upon the alloy there could be more springback on the fatter bullet. It looks like the measurements were taken with calipers, which round. So the difference in size is likely not that large.

Plus it could have been such a small variance in brass that one was thicker than the other since that wasn't measured to the precision that would detect it.

Lot of variables like I said but I feel it proves that the FCD usage does make it more likely to smoosh than not using it in my specific instance.

[357shooter]

OK maybe someone can help me out here. With the exception of. 45acp for which I use a Dillon taper crimp die I use Lee's FCD on almost all of my cast bullet loads and *some* of my jacketed loads.

I get exceptional accuracy from all of my big bore rifles...444....458...etc using the FCD and my cast bullets.

I also shoot a LOT of. 38 special and. 357 Magnum handguns and I do use a light FCD crimp to avoid setbacks. All of my cast bullets are sized to the slugged barrel and I just can't envision how a small crimp, at the mouth of the case, can resize the entire bullet --- please set me straight on what my little mind can't comprehend guys.

I know if you overcrimp you can really screw things up but have had such good luck with the FCD as opposed to using the built-in crimp on the seater dies I'm having a tough time understanding.

Art

I'm of the camp that says if it isn't broken, don't fix it. If the FCD is working for you then keep using it.

For me and my guns, oversize cast shoots best. My 38/357's are all .003 over groove size, which gives me the best accuracy and also big enough to get swaged down by the FCD. Yours are sized to the groove size and won't get swaged down at all.

[Tazman1602]

I'm of the camp that says if it isn't broken, don't fix it. If the FCD is working for you then keep using it.

For me and my guns, oversize cast shoots best. My 38/357's are all .003 over groove size, which gives me the best accuracy and also big enough to get swaged down by the FCD. Yours are size to the groove size and won't get swaged down at all.

I agree with that one. My barrels have all been slugged and I also size. 002 oversize. I experience no leading ever and get good accuracy from my handguns.....but I'm a lousy handgun shot!

Art