I was going to put this in whatchya doin' today, but thought it really deserved to be part of this thread.
I have a great appreciation for the Lee neck sizing collet dies. I do not own multiple rifles in the same caliber so the need for full-length resizing is not necessary for me.
Enter the .218 Bee. I ordered the Lee 3 die set in .218 B and since they don't offer a collet necksizing die in that caliber, I ordered one in .22 Hornet.
The ID and OD of both cartridges is identical. The differences are the shoulder angle, the length of the neck, the OAL of the case and of course, the body diameters. The collet dies only care about OAL of the case, neck ID and OD, the shoulder angle and the length of the neck.
The Bee is shorter than the Hornet on both OAL and neck length. This means that the Hornet die must be modified to use with the Bee case. Nice thing is it is easy to figure out by fudging. You put a washer on top of the shell holder in the press after you slip a case into the holder. The washer will contact the closing collet sooner, thus making it work with the Bee case. You can change the thickness of the washer until you get what you want. Then you can measure things to confirm.
Of course, I thought there might be the possibility that no modification would be necessary, and I slipped a case into the shell holder and ran it up into the die lightly. When it came out, the shoulder had been pushed back. So, that gave me a measure of how thick the collet had to be lengthened. Without the spacer, the case is pushing the collet up, but is weak so it gives, and the shoulder moves back until the shell holder makes contact and then the collet closes and sizes the neck. Of course, I did not figure that all out on the first try. Gray hair has slowed down my ability to visualize what is doing on inside of mechanical devices and I crunched another 3 new cases in the learning/testing process.
Since you cannot see what is going on inside the die, I did remove the closer and the mandrel and ran the case up into the collet until it touched to see how far the shell holder was from the collet. Dug thru my misc washer drawer and an old spark plug washer did the trick. It measured 0.050". But putting a washer over every case to be deprimed and sized is a PITA and runs a high risk that the gray-haired operator will forget and push the shoulder back on the case or two... or ten. So, the die had to be modified.
Now, you might be thinking, "Gee the Hornet is longer than the Bee. Shouldn't the die have to be shortened?". The answer is no. The neck on the Hornet is longer but from the case base to where the neck begins, the Hornet is shorter by 0.080" compared to the Bee. This is why the shoulder crashed into the bottom of the sizing section on the collet with a Bee case. And, difference in the base to start of neck location is greater than the difference in OAL of the cases.
Here is a picture of two Bee cases. One on the left is per spec and the other on the right shows the shoulder pushed back after crashing into the bottom of the collet sizing section.
Here are a couple pics of a good case and a damaged case in the same collet. It is subtle, but you can see that the damaged case is deeper in the collet. Damaged case on left, good case on the right. The other thing to keep in mind is that the collet is open. When it closes, it will crunch a bit of the shoulder where it transitions to the neck. So, you cannot have the neck butting tight to the bottom of the sizing area inside the collet.
Measuring the depth of the case mouths from the top face of the collet above gave 0.090" for the damaged case and 0.150" for the good case. That means I need a 0.060" spacer... kinda. Remember, the collet is open. I'm not sure how much more clearance I need for a good case not to crunch the shoulder. And, these are all new cases. OAL might vary from case to case. I could measure, but I have already damaged 4 cases so I was not willing to crunch any more. But I found another way.
Here is the mod I made to the die. I took a generic steel washer, soldered it to the bottom of the collet and then machined the ID and OD to be flush with the collet walls. The spacer thickness is approximately 0.075" including the solder joint. Yes, that is more than I need based upon the above dimensions. But remember that I said that the collet was open when I took those measurements. So, another 0.015" gives some added clearance for the shoulder inside the collet at the bottom of the sizing area.
When the mod was done, I put the die back into the press and put a good case in and ran it thru the size. It came out perfect.
So, to confirm, I pulled the closer and mandrel out of the die. I took another new case and put it in the collet. From the mouth to the top of the collet I measured 0.095". Then, I put that same case in the press and ran the case back up into the collet with the closer and mandrel removed and measured that same distance. I measured 0.140. Here's the view. The end of my caliper just fit inside the die. So, I have 0.055" of play. Might need that after these are fire-formed to my chamber.
So, I now have a .218 Bee collet neck sizing die. Of course, none of these cases have been fired and formed to my chamber. Those 4 damaged cases should fire form back to the correct shoulder config. Once all the cases have been formed to the chamber, I'll revisit this subject to be sure the shoulder is not going to butt up against the bottom of the collet. I think I'll be okay. But only testing will tell. Once all that is done, the cases will all get trimmed to the same length.
Another nice feature of the new Lee collet dies is they do not resize the very top of the neck. I was going to make an M-die for the Bee, but I tried both a GC bullet and a PB bullet and both slip into the first .030 or so of the neck like they would with an M-die. So, it looks like I'll not need the M-die step when I reload the cases. It will simply be deprime/neck size, clean the pockets and prime, fill with powder and seat a bullet. If I decide to breach seat, seating the bullet will be replaced with cap the neck with florist foam.