Lee 9mm factory crimp die - Input/Suggestions please.

So, it seems I have found the issue. How? I picked up another 9mm Luger LEE FCD while I was buying powder this aft. That's right, I now have 3. Luckily they're 25% off right now.
Anyhow, I went straight to work when I got home and loaded up 20 test rounds to put through the new die, and low and behold they came out looking like they should. Odd.

So I took them both apart, compared and noticed a few things:
1. As smooth as the inside of the crimp bushing from the old die appeared at first, it is not as smooth as the new one(see pics below). There is noticeably more texture in the tapered section of the crimp bushing on the old die. Previously I did not consider this to be rough, particularly since both of my old 9mm LEE FCD's were exactly the same in this regard.

2. The dies had a slightly different stamp (see pic below). The one on the left (G4) is the old die. The one on the right (B7) is the new die. What does this mean? Maybe just different years or production facilities or production runs, who knows...

Crimp bushing from the old die.


Crimp bushing from the new die.


Stamps


Finished round. Crimp to 0.373" from 0.377" at seating surface. Even with a heavy crimp, it looks much better than before.
 
4n2t0 said:
I still think you're crimping too much. Just for $hits and giggles crimp to .379 and see if the marks go away. If they don't go away see if the taper in the die is rough or galled with brass. Just unscrew the adjustment plug and look at the ring.

Here's a image for you, does it look familiar?

lee_fcd_case_mouth_zps404063e4.jpg
Click to expand...

Hehe, I'd love to crimp to 0.379" but every loaded 9mm round I've ever measured comes out to 0.376(5)-0.377" at the case mouth right over the seating surface of the bullet. When I crimp it's usually to 0.374-0.375".
My calipers tend to measure out my 9mm and 45ACP to 0.356" and 0.451" quite consistently so I'm pretty confident in the measurement. Maybe we're loading a different make of bullet?

But to answer your question, yes, the casings in that pic do look familiar.
 
Northernfly said:
Hehe, I'd love to crimp to 0.379" but every loaded 9mm round I've ever measured comes out to 0.376(5)-0.377" at the case mouth right over the seating surface of the bullet. When I crimp it's usually to 0.374-0.375".
My calipers tend to measure out my 9mm and 45ACP to 0.356" and 0.451" quite consistently so I'm pretty confident in the measurement. Maybe we're loading a different make of bullet?

But to answer your question, yes, the casings in that pic do look familiar.
Click to expand...

I'm not sure why .379 scares you. I load the same CamPro anywhere from .377-.379. The crimp, or more appropriately taking out the bell, in 9mm doesn't do anything other than headspace against the chamber cartridge stop.
 
4n2t0 said:
I'm not sure why .379 scares you. I load the same CamPro anywhere from .377-.379. The crimp, or more appropriately taking out the bell, in 9mm doesn't do anything other than headspace against the chamber cartridge stop.
Click to expand...

It doesn't scare me at all, it's just that a 0.379" diameter simply does not exist on any of my seated cartridges until ~ half way up the case. After I seat the the bullet with my Lyman seating die, the diameter of the case mouth is already 0.376-0.377" so I can't crimp down to 0.379". Maybe I 'm misunderstanding you.
 
Man, 2 bad dies in a row, either the whole lot is bad or you've had some serious bad luck.

One thing though, if you check Lee's website, you can order these plugs for free. So if you order 2 of them, you can get 2 functionnal dies that you can sell in the EE.
 
Waaaaay too much crimp in my opinion. The mouth of your case where it meets the projectile should be square as most of the major handgun calibers headspace on the mouth of the case.

I wouldn't be surprised if you have FTE/FTF problems.

If I were you I would send back that crimp die and tell Lee to send you a U-die. Straight edges every time and you will never have to worry about set back.

my $0.02.
 
Northernfly said:
It doesn't scare me at all, it's just that a 0.379" diameter simply does not exist on any of my seated cartridges until ~ half way up the case. After I seat the the bullet with my Lyman seating die, the diameter of the case mouth is already 0.376-0.377" so I can't crimp down to 0.379". Maybe I 'm misunderstanding you.
Click to expand...

I'm confused by your response. What is your sized case mouth measurement? What is you expanded/belled case mouth measurement?
 
A taper crimp isn't a crimp at all, it is just to close up the case mouth flare, and should approximately .002”+/- smaller than case diameter before crimping.

Your bullet grip is controlled by the inside case diameter being smaller than the bullet, and the taper crimp is nothing more than streamlining the case mouth.

The taper crimp is critical on thin plated bullets and if over done will break through the thin plating.

Bottom line, with a taper crimp less is more.

Crimping 9MM Luger Cases for Reloading
http://www.tannersbrass.com/crimping.aspx

Below two factory crimps on the left and reloaded crimp on the right.

blazer_brass_factory_bullet_crimp_left_reloaded_crimp_right_200.jpg
 
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DWiB said:
Waaaaay too much crimp in my opinion. The mouth of your case where it meets the projectile should be square as most of the major handgun calibers headspace on the mouth of the case.

I wouldn't be surprised if you have FTE/FTF problems.

If I were you I would send back that crimp die and tell Lee to send you a U-die. Straight edges every time and you will never have to worry about set back.

my $0.02.
Click to expand...

Howdy!
As I'd mentioned in the original post, the RCBS TC seating die that I have been using for some time does a really nice job of applying a very light crimp of ~0.001" during seating, which is just enough to close up the case mouth(remove the bell/flare) after the expansion step. There is plenty of case rim available for headspace and no bulges in the casing , therefore I have not had any FTE or FTF's. I never actually used the LEE FCD on live rounds because my test rounds were so chewed up.
This thread was created because, to give the same results as the RCBS die, my old Lee FCD's were chewing the hell out of the casing mouth and I couldn't figure out why. The apparent overcrimping in the original picture was the result of the LEE FCD giving the same amount of crimp (or closure) as the RCBS die was giving and it just seemed wrong. I'll look in to that U-Die, thanks!

bigedp51 said:
A taper crimp isn't a crimp at all, it is just to close up the case mouth flare, and should approximately .001 smaller than case diameter before crimping.

Your bullet grip is controlled by the inside case diameter being smaller than the bullet, and the taper crimp is nothing more than streamlining the case mouth.

The taper crimp is critical on thin plated bullets and if over done will break through the thin plating.

Bottom line, with a taper crimp less is more.

Crimping 9MM Luger Cases for Reloading
http://www.tannersbrass.com/crimping.aspx
Click to expand...

See above response and thanks for your reply.
I won't disagree with anything you've said since it seems to follow everything I've ever read about crimping. At the advice of another responder to this thread I pulled one of my bullets from a loaded round produced with my RCBS die(what I consider to be properly crimped) and looks very much like the bullets on the left in your picture, maybe a bit more of a ring. Certainly no deformation like the bullet on the right.
 
Northernfly;14299066 See above response and thanks for your reply. I won't disagree with anything you've said since it seems to follow everything I've ever read about crimping. At the advice of another responder to this thread I pulled one of my bullets from a loaded round produced with my RCBS die(what I consider to be properly crimped) and looks very much like the bullets on the left in your picture said:
Your taper crimps with your RCBS die looked good to me, it is the plated bullets that can cause a problem. And pulling a bullet from a loaded round is a very good way to "SEE" what your doing.

You could also try polishing the crimping plug and see how it works.

Below a brand new RCBS rifle die expander closeup macro photo, and had to be polished to keep it from "eating" neck brass.

5Rqdvuh.jpg


My biggest problem when reloading is my chronologically gifted eyesight and "seeing" what I'm doing. (and they don't make braille dies) :mad:
Click to expand...
 
bigedp51 said:
Your taper crimps with your RCBS die looked good to me, it is the plated bullets that can cause a problem. And pulling a bullet from a loaded round is a very good way to "SEE" what your doing.

You could also try polishing the crimping plug and see how it works.

Below a brand new RCBS rifle die expander closeup macro photo, and had to be polished to keep it from "eating" neck brass.

5Rqdvuh.jpg


My biggest problem when reloading is my chronologically gifted eyesight and "seeing" what I'm doing. (and they don't make braille dies) :mad:
Click to expand...

Nice Macro!

The sizing/decapping die from my RCBS 9mm set is in the process of being sent back for replacment or polishing or whatever the heck they do. It was leaving great big grooves down the outside of my brass. It's a shame they don't all come the way they should.

And I'll have to look up the process for polishing a die. I've been reading it can be done, but have never attempted it myself. I just try to keep mine clean and free from grit and grime and shavings and such.
 
Northernfly said:
Nice Macro!

The sizing/decapping die from my RCBS 9mm set is in the process of being sent back for replacment or polishing or whatever the heck they do. It was leaving great big grooves down the outside of my brass. It's a shame they don't all come the way they should.

And I'll have to look up the process for polishing a die. I've been reading it can be done, but have never attempted it myself. I just try to keep mine clean and free from grit and grime and shavings and such.
Click to expand...

Takes about 2 minutes and cost less than shipping the dies. Here's how: https://www.canadiangunnutz.com/for...rnady-dies?p=13920362&viewfull=1#post13920362

You can read the whole thread but in summary I had to polish a Hornady Ni-Ti resizing die because Ni-Ti isn't as good as cheap carbide.
 
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