Question about neck sizing dies?


September 18, 2011, 06:27 PM
I used my Lee neck collet die for the first time today, and had sized about 10 cases...really liked it, until I pushed too hard on the press, and pushed all the inside pieces up about a quarter inch and stripped the top threads.

Yes, I know, you must ask, "How could one do that?" Yes, I read the instructions, and adjusted correctly, I simply pressed too hard. I suppose I am used to the pressure required with standard FL sizing dies.

Here is my question...Do other neck sizing dies use collets like the Lee, or are they a sizing ball that requires lube, the RCBS or Redding, for instance?

If you enjoyed reading about "Question about neck sizing dies?" here in archive, you'll LOVE our community. Come join today for the full version!
September 18, 2011, 06:45 PM
I simply pressed too hard. If you were able to break it by pushing too hard, it was adjusted improperly.

Lee is the only one that uses a collet, but some use bushings, eliminating the expander ball.

September 18, 2011, 06:47 PM
If your dies are adjusted correctly, you can't break anything. Once your press bottoms out, that's it. Walkalong was correct, dies are not properly adjusted.

September 18, 2011, 08:12 PM
I am sure it was my fault, there is no doubt there...but I am a bit fuzzy on how to adjust the die in the press.

And it may have been adjusted improperly, but I did follow the instructions. I screwed it into my RCBS press until it made contact with the shell holder then two additional turns as the instructions said, but it was not resizing the neck, so I backed it off maybe a quarter turn and it was sizing just fine until I pushed too hard.

In the instruction flyer, it showed that if the shoulder is flared or mushroomed, then the die is improperly adjusted...I mean I clean broke the die, but did no harm to the brass case.

I asked Lee via email if the warranty would cover it...if not, I will simply buy another and try again.

Any advice on the nuances of adjusting this neck collet die is appreciated.

September 18, 2011, 09:14 PM
Since Lee dies are fairly cheap, you won't be out too much money to replace you die but you might consider a traditional neck sizing die. For neck sizing, all you need is dry lube which isn't too messy.

September 18, 2011, 10:58 PM
In the opinion of many experienced reloaders, Lee's collet die is THE best neck die on the market, at any price, but it isn't a simplistic 'push the case in, pull the case out' thing as all others are. Truth is, we really can't properly adjust ANY die by a fomula, all the 'instructions' can do is get is in the right ball park; the collet adds a moving part and that has to be learned by feel. Most of us get passed the learning curve without breaking anything but not all of us! Once you do get the feel of it you will have no more problems. Or shouldn't have.

It takes less lever pressure than many think to fully squeeze case necks down to the mandral and that's as far as they can go; pushing harder only stresses the die for no change. That soft alum top cap is specifically designed to strip out if we apply too much pressure, it acts like an electical fuse to prevent damage to the die body or press. And it works. Call Lee's customer service, they will send you a replacement.

September 19, 2011, 06:55 AM
That soft alum top cap is specifically designed to strip out if we apply too much pressure, it acts like an electical fuse to prevent damage to the die body or press. And it works.

Yes, that is exactly what happened...wish that top cap were steel. I would rather have trashed a brass case than the die.

I contacted Lee by email on their web site; awaiting an reply.

Thanks for the advice and info...I will try again.

September 19, 2011, 07:38 AM
I found the same burrs etc on my collet dies many years ago. Cleaning them up made things smoother. It still has to be adjusted properly of course, and ranger335v is right, no directions can get you exactly right, just in the ball park where,once there, you must finalize it for your self.

Great pics as usual big ed.

September 19, 2011, 09:22 AM
I am happy with the results of getting the "special" 0.001 undersized mandrel from Lee. Gives a tighter bullet fit.

September 19, 2011, 12:55 PM
Jasper1573 you just need to get another cap (the aluminum part that stripped) from Lee and start over. Re-read the instructions. You had the die adjusted correctly before you backed it off a quarter turn". The die can not take the kind of pressure applied by a press going "over center". It clearly states this in the instructions sheet. You may have been not applying enough force when it "was not resizing the neck". The necks may have been being resized, though, don't just use eyesight. Measure them or try to place a bullet into the neck to check. The crushed shoulder isn't a sign of maladjusted dies, it's a sign of stuck collet fingers. When you install the new cap, clean and inspect all of the internals. As said before, the collet may need to be deburred and / or buffed. Make sure that there is clear space between the fingers. Hope this helps.

September 19, 2011, 03:56 PM
And I have been considering buying one of those dies? I think I'll stick to necking and bumping with my FL die. I haven't broken anything yet, and after 30 + years of doing it this way, I've got a good feeling I never will break anything.
Seriously, are the collet dies difficult cumbersome to opperate or prone to problems such as this?

September 19, 2011, 05:12 PM

When the Lee Collet die is set up correctly you will have "MUCH" less neck and bullet run-out than any other standard type reloading die.

The following was from the 1973 Speer reloading manual on setting up your reloading dies for bench rest accuracy.

"More reloaded cartridge cases have the necks of the cartridge case pulled off center due to the fact that the decapping rod is locked down off center in the die creating crooked necks and excess bullet run out."

Example below of a cartridge neck pulled off center by the decaping rod/expander button.

Below, a cartridge case with a straight neck and very little bullet run out.

A cartridge case with .001 -.002 run out is considered capable of having bench rest accuracy.

On the Lee Collet die the mandrel floats and is self centering and thus produces less neck and bullet run out which decreases your group size.

The problem is the Lee Collet setup directions are "generic" and not every reloading press is exactly the same. The second problem is most people think that the same amount of "force" is required to use the Lee Collet die as you do on a standard type resizing die.
(one finger pulling on the handle is more than enough) And don't let your pet Gorilla use your Lee Collet dies. :banghead:

Watch the YouTube video below and learn.

"Comparison of the Lee Collet neck die and the Hornady neck die"
(or how the expander button pulls your necks off center) ;)

September 19, 2011, 05:31 PM
One thing I appreciate about Lee equipment, if you break something, they'll replace it, usually at no cost. I broke the cast aluminum bracket that attaches the handle to the ram on my press, called Lee customer service, and had a new one shipped out the next day, no charge.

September 19, 2011, 09:46 PM
Well, this is the first time I have posted a question and received so many substantive, if somewhat abrasive, replies. Now, everyone play nice...I really appreciate all the info and input and find it all very helpful.

Lee is sending me a new aluminum top cap, and I must say that I agree with all of the advantages of the Lee Collet neck sizing die; that is, no lube required, less case/neck run out, just less work and time overall.

Yes, figuring out the die may take some pain, but I believe if your cases are fire formed and used in the same rifle, it is worth the learning curve and effort.

Mr. FGuffey, you have my condolences...thanks for your opinion(s).


T Bran
September 19, 2011, 10:33 PM
When I first used this die it didnt size down far enough and my seater would stick on the bullet a bit sometimes pulling the bullet parrtially back out of the case. I posted and received the you set it up wrong replies. They were correct. I did not realize that part of set up is polishing the mandrel down to a smaller diameter than the bullet. In my case it was .223 Rem the bullet diameter is .224 the die was sizing .222 not enough tension. I chucked the mandrel in a cordless drill and spun it in some 600 grit sand paper untill it was .2205 was shooting for .221 but it works fine now. Just pull handle till it comes to a stop and that is as far as it can size it down without polishing mandrel some more.

September 20, 2011, 08:16 AM
This thread has been heavily moderated.

I am not sure what derailed this thread, but it went so far off the tracks that it would take days to sort through what posts were helpful and what posts were not so some may be missing that were not necessarily off topic completely.

Some members may hear from the Staff regarding their posts, some may not.

Please let's try to remember the name of this place, The High Road.

If you enjoyed reading about "Question about neck sizing dies?" here in archive, you'll LOVE our community. Come join today for the full version!