3 or 4 dies?

[Turbocharged]

I want to start reloading my own ammo (pistol primarily, .45 ACP and .40 S&W, then maybe 9mm and .223 Rem. later) and am having trouble deciding whether or not the carbide 4-die sets or the carbide 3-die sets are better for me. I understand that the 4th die separates the crimping process, but don't know why this is necessary.

As an added note. I planned on purchasing the Lee 4 Hole Turret press with auto-indexing (the deluxe kit), then buying both .40 and .45 dies with an extra turret.

 

[RidgwayCO]

I have the four die sets (or have added a crimp die to my three die sets), because I like to crimp as a separate step. It's easy to do with the Lee Classic Cast Turret.

The reason for crimping as a separate step is because when you seat and roll crimp simultaneously, the case is scraping the side of the bullet just before the bullet is fully seated. This does nothing for accuracy.

I imagine there is less an issue with a taper crimp. Some people always seat and crimp at the same time, and seem happy with the results.

That's the best thing about this hobby, you can be just as demanding as you see fit!

 

[Hylander]

Get the Lee 4 Die set !
Crimping in a seperate step is Much better.
As RidgwayCO said, Crimping while seating causes the Case to cut into the bullet as it is finishing seating, this hurts accuracy and can cause lead fouling and other issues.
Also the that fourth Lee Die makes sure the case is properly sized so the Ammo will fully chamber properly.

 

[zxcvbob]

I crimp and seat all handgun cartridges in one operation. The only thing I use a Lee FCD for is post-sizing .38 Specials and .357 Magnums because occasionally a bullet bulges the case enough that they are hard to chamber.

I had a 9mm FCD but I sold it. I still have one for .45 Colt, but it was a waste of money.

 

[Nnobby45]

The reason for crimping as a separate step is because when you seat and roll crimp simultaneously, the case is scraping the side of the bullet just before the bullet is fully seated. This does nothing for accuracy.

Nice to hear from someone who understands what happens when you try to crimp a bullet that's still in the process of being seated.

If you had to load on a single stage press, I could understand the temptation to save time by having a combination seat/crimp die. But if you have a four stage press, use the 4 die set.

Yes, I know that some have used the combo dies for years and swear by them.

 

[Turbocharged]

Thanks for the explanation...exactly what I was looking for. The 4-die sets it will be then.

 

[zxcvbob]

when you seat and roll crimp simultaneously, the case is scraping the side of the bullet just before the bullet is fully seated. This does nothing for accuracy.

When you seat and roll-crimp at the same time, the mouth of the case is in the crimp groove or cannelure when the bullet is almost seated. There's nothing there to scrape. (nice try though)

The real advantage of using a separate crimping die is ease of set-up because you can adjust the crimp and the bullet seating independently. If that's worth $10 to you, go for it.

 

[Atticus Thraxx]

I run a 3 hole Lee with seperate crimp. I use another press to De-cap/re-size then tumble prior to trimming/prep. Seems to work for me anyway.

 

[CrustyFN]

If that's worth $10 to you, go for it.

Actually the sets are only around $7 difference but yes it is worth it to me. I don't know anybody that loads on a four or five station press that doesn't use a separate crimp die. I'm not saying it's a must but there must be something to it if most people are doing it that way.
Rusty

 

[BigJakeJ1s]

Zxcvbob has it right, for roll crimping. Think of it this way (for roll crimping): the crimp ring and the seater plug have a fixed relationship during seating and crimping. So if the crimp ring is turning the mouth in, it is doing so at exactly the same point on the bullet, cannelure or not. Another way to look at it is as if the bullet were already at the top of the die, against the seating plug, and you were pushing a case mouth up around it. The case mouth hits the crimp ring and stops going upwards, instead rolling inwards: there is no scraping.

Taper crimping is a whole different manner, since the case mouth does continue upwards after the crimping starts.

However, if you have a progressive with five stations (including powder through expander) or more, then there is no alternative cost to using a separate crimp die, and the benefits of easier, independent adjustment of crimp and seating depth, and relative insensitivity to case length variations are probably worth it. If you have only 4 stations (or 5 without powder through expander), then crimping separately consumes a station that could be better used to allow a powder check die in the setup.

Andy

 

[Nnobby45]

When you seat and roll-crimp at the same time, the mouth of the case is in the crimp groove or cannelure when the bullet is almost seated. There's nothing there to scrape. (nice try though)

Unless, of course, you use one of the many bullets manufactured without a cannelure.

 

[Nnobby45]

When you seat and roll-crimp at the same time, the mouth of the case is in the crimp groove or cannelure when the bullet is almost seated. There's nothing there to scrape. (nice try though)

Unless, of course, you use one of the many bullets manufactured without a cannelure. Berry bullets and Ranier, to name a couple.

 

[DWARREN123]

I use the Lee 3 die set for 40 S&W and have not had any problems. I like how they work and see no need for me to change.

 

[Smaug]

Nnobby45 - The Lee Factory Crimp dies for revolvers make their own cannelures if there isn't one on the bullet already.

I don't know if this was ever answered, but one poster said most people are using 4 die sets. The purpose of the crimp for revolver ammo is to keep the bullet from un-seating during recoil.

In autos, the front of the magazine does this and no crimp is necessary. I apply a light taper crimp anyway. Just enough to where I can see the leading corner of the case mouth is a bit shiny. This keeps the bullets in place in case I chamber them more than once.

Take note that crimping increases pressure, so don't overdo it.