Lee collet questions

I use the collet die only, until the brass needs to be bumped back with a FL sizer. I judge this to be when the bolt starts to develop resistance. To me this is the great advantage of the collet die, minimal stress on the brass and minimal brass prep work.
Exactly the way I do it as well, brass lasts till primer pockets loosen for me.
 
Using the body die the cases will grow in length. When the case walls are moved in the brass moves forward and pushing the shoulder back moves brass in to the neck. If the body die does not contact the shoulder it will be too long to chamber. When setting up the Collet Die I set it loose to start and slowly lower it until I get the amount of sizing I need and no more with the press ram fully extended and bottomed out. I also size, rotate 1/3 of a turn and repeat twice more. Most concentric way I've found to size brass.
Also get the best ES/SD numbers.
 
Using the body die the cases will grow in length. When the case walls are moved in the brass moves forward and pushing the shoulder back moves brass in to the neck. If the body die does not contact the shoulder it will be too long to chamber. When setting up the Collet Die I set it loose to start and slowly lower it until I get the amount of sizing I need and no more with the press ram fully extended and bottomed out. I also size, rotate 1/3 of a turn and repeat twice more. Most concentric way I've found to size brass.
Also get the best ES/SD numbers.
Using the body die the cases will grow in length
It will be minimal using a body as Brass will not "flow" or move forward from the pressure you apply from a press , It will "flow" or grow in length from the extremes of firing and it will "stretch" and grow in length from being pulled by the expander ball in conventional FL die sets
 
Last edited:
If you size it with any die FL or body die without pushing the shoulder back it will lengthen the case. Like I said, if it pushes the case wall in any amount, it will lengthen the case base to datum point on the shoulder. The very reason you can't partially FL size.
 
the expander does not cause the brass to lengthen and there should not be any "pull" from the expander if you have lubed the case neck. Expanding the neck by any means will shorten the brass slightly. In other words; make tubes narrower they have to get longer and/or thicker, make tubes wider they have to get shorter and/or thinner.
 
If you size it with any die FL or body die without pushing the shoulder back it will lengthen the case. Like I said, if it pushes the case wall in any amount, it will lengthen the case base to datum point on the shoulder. The very reason you can't partially FL size.
And no where in this thread has anyone said anything about FL sizing without bumping the shoulder, so where a we at now ?
 
the expander does not cause the brass to lengthen and there should not be any "pull" from the expander if you have lubed the case neck. Expanding the neck by any means will shorten the brass slightly. In other words; make tubes narrower they have to get longer and/or thicker, make tubes wider they have to get shorter and/or thinner.

there should not be any "pull" from the expander

Oh but there is as the ball "drags" through the neck if you will "expanding" it is pulling upward stretching the neck making it longer no matter how much or what kind of lube you use , you cant have one without the other, This is why you trim after all brass prep is done with standard FL resizing, one of the advantages of body dies and Lee Collet dies is to minimize trimming and less stress on your brass
 
I use the collet die only, until the brass needs to be bumped back with a FL sizer. I judge this to be when the bolt starts to develop resistance. To me this is the great advantage of the collet die, minimal stress on the brass and minimal brass prep work.

I have several standard 3-die sets, but have never used the neck sizers that came with them. After seeing it recommended, I ordered a couple of Lee collet does, and was going to follow the same process Graywolf mentions here to avoid FL sizing each time. But after reading some of the detailed steps and comments here realize just how much I don't know. Some of you folks are taking many more steps per case than I am.

I think I'll try to keep it simple and stick with the Lee Collet die, FL sizer when needed, and a good seating die, with a pass through a Lee FCD if needed.

If someone can educate me on a better process and the reasons for it (on a hunting rifle anyway, I don't have a Precision rifle as yet) I'm open to learning about it, but simpler seems better generally.
 
I have several standard 3-die sets, but have never used the neck sizers that came with them. After seeing it recommended, I ordered a couple of Lee collet does, and was going to follow the same process Graywolf mentions here to avoid FL sizing each time. But after reading some of the detailed steps and comments here realize just how much I don't know. Some of you folks are taking many more steps per case than I am.

I think I'll try to keep it simple and stick with the Lee Collet die, FL sizer when needed, and a good seating die, with a pass through a Lee FCD if needed.

If someone can educate me on a better process and the reasons for it (on a hunting rifle anyway, I don't have a Precision rifle as yet) I'm open to learning about it, but simpler seems better generally.
I agree 100% and I'm not trying to stir the pot, What your doing is correct and works flawless and that's the point I'm trying to make, It seems every thread here any more gets derailed and goes a completely different direction, The original post was answered in the first answer and now we are on to partial FL resizing, Regardless, I'm with you on keeping it as simple as possible
 
sorry to belabor the point.
Loaders that do not use expander balls or that use turning arbors or expander mandrels (push instead of pull) also observe case Length growth.
The cases don't get significantly shorter In these situations because of the drag due to the "push". Case length increases (for our purposes) as result of reducing the diameter of the case and neck when it is sized down and unrestrained in length. Steep shoulders like those found on Akley improved cartridges don't grow as quickly as gradual bottlenecks do partly because the steep shoulder in the die behaves somewhat like a restraint in the length of the body. The brass that does move from the body of these cases often creates a thicker ring at the neck-shoulder junction Instead of adding to the overall length of the case.

if your expander is pulling hard enough to measurably change the length of the case then it is must also be reducing the diameter of the case (or the thickness of the brass).

interestingly when a cartridge is fired and it expands to fit the chamber, it gets a bit shorter but because of It's geometry and how the material behaves the brass walls thin much easier than shorten so we tend to observe the brass thinning at the weakest part of the case ( ahead of the web) to make up for some of the increase in diameter.
 
Last edited:
Better watch out!!! Nobody here has asked about using an expander mandrel to get neck tension consistent. If you're just wanting to load and shoot, go ahead.
 
Ok so now I've got it setup and it sizes the neck perfect every time. Seems to be more consistent then the previous neck bushing I was using. Only thing that I'm noticing is that there are little hair line impressions on my brass that are kind of ruff, not to bad but noticable. My dial on the Concentricity gauge send to bounce not going across them. Thoughts???
 
Warning! This thread is more than 5 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Recent Posts

Top