I have no means to measure neck tension. Only going by what seating the bullet feels like.
That's kinda like driving down the highway without a speedometer, calipers aren't that expensive and how can you reload without them?
I have no means to measure neck tension. Only going by what seating the bullet feels like.
I had to disassemble the die and sand & polish out the chatter marks from when Lee turned the angled parts of the die on the lathe.
I'd say that 80% of the chatter was on the bottom part (the one with the slits). Wasn't too bad on the top part that buts up to the cap.
The chatter marks make them stick....you'll want them smooth as glass.
If you made a replacement cap for the factory aluminum one that sheared on you, then certainly you have a lathe... with some fine sand paper will make quick and efficient work of that
Chuck the mandrel in a lathe, get a strip of emery cloth, and a good micrometer, away you go.
The 7.5x55 mandrel has a different part number than the 308 since the Swiss round is 4 mm longer than the 308.
That's kinda like driving down the highway without a speedometer, calipers aren't that expensive and how can you reload without them?
I have calipers. I was more thinking of the bullet seating pressure.
I have calipers. I was more thinking of the bullet seating pressure.
Cases are annealed.
I have no means to measure neck tension. Only going by what seating the bullet feels like.
I got a Lee Collet neck sizing die for my 303.
The instructions say to adjust the die so the press does not cam over. Also says to apply ca 25 lbs of pressure to the handle. Apparently my perception of 25 lbs is different from what the die was designed for.
I find that no matter how much pressure I put on the press handle, the neck tension when seating the bullet is very light. I have been crimping bullets after seating because the neck tension seemed so light.
Anyway, after sizing less than 100 cases, the top cap of the collet die shed its threads. I ended up making a new top cap out of steel (benefits of a home machine shop). I have reset the die in the press so the press does cam over but only with a small amount of pressure. To me, this allows the calming pressure to be much more consistent from case to case.
Lee's instructions for the neck sizing collet die link here:
https://leeprecision.com/files/instruct/RM3512.pdf
As others have mentioned, the Lee instructions state to not cam over. You do not need "extra" force for the collet to press the brass neck against the steel mandrel. Brass is soft enough that you are exerting more force than you may think. But brass springs back, so it is recomended in the instructions that you rotate the case in the shell holder (maybe a quarter or half turn) and press a second time. I do this with my collet dies and it becomes muscle memory to rotate the case (no thinking required) and takes only a couple seconds more per case.
The undersized mandrels have been addressed above (and in the instructions), and can be ordered from Lee.
RE: the die (collet) sticking in the up position and buckled shoulders: The Lee instructions address this issue, it is easy to remedy.
I read somewhere, (its not in the Lee instructions) that the outside of the collet top should be greased so it can fucntion better inside the upper part of the die. Just a little grease, you don't need alot. This grease on the outside of the collet will not leak into the brass (if it does you applied too much), so no worries there. The grease makes the mechanism work much smoother, and I never had it stick in the closed position once I greased the collet.
My preference is to decap separately and I recommend do not use the neck sizing collet die for decapping. With the primer out before hand, you can get a better feel for the full process of what's happening with the neck as you move the ram and the collet closes.
I found many comments on this thread to be helpful. I have an elderly 9.3x57 rifle - I had to create a "flair" to seat 285 grain cast bullets. Likely my klutziness, but upon first chambering, those rounds "dragged" - but second time in they did not - so I presumed there was enough "flair" still left to drag within the chamber neck, which pressed that in. Lee does not make a FCD die for 9.3x57 - so I got one for 9.3x62 - seems to have similar "squeeze" concept as their collet neck size dies - but I am still noodling how to cut that one down to squeeze the necks, after seating cast bullets. The FCD appears to be driven by contact with the shell holder - is no "cap" on the top of it. I am not seating to a crimp groove in those bullets - so pretty much leaves FCD as about my only option - I think. I also found a 9.3 "M" die, which might solve the issue by itself - to be tried, yet.
All the reading I did regarding cast bullets was you need to use a Lee Universal Expander Die and then get a series of NOE expander mandrels to bring the neck up to the right size to seat cast bullets without shaving the bearing surface. The NOE expanders include a flaring section.
I have got all the components and am just beginning to experiment with this setup. Seems to work really well so far.
Adjusting to cam-over seems way more consistent and reliable to me. Trying to apply the same amount of pressure by hand is stupid and inconsistent.
Adjusting to cam-over seems way more consistent and reliable to me. Trying to apply the same amount of pressure by hand is stupid and inconsistent.
What is why you use 25 lbs force, so you resize to the mandrel diameter. Trying to size by feel for neck tension is just stupid