help with lee neck sizing dies.

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crout

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I consider myself half intelligent but for the life of me i can't seem to figure out the neck sizing dies. the instructions are simple and clear but i can't get them to neck size my brass properly.

they are designed so you can size as much of the neck as you want but suggest 3/4 of the neck for best accuracy. with both my calibers it sizes all the neck or none and it doesn't give enough neck tension to grip a bullet tight. and i feel as though i'm pushing the shoulder down a bit.

are my dies no good or am i doing something wrong?
 
What kind of press are you using? Is it the type that 'cams over' at the end of the stroke? If so, those need to be set a turn tighter or two so they don't over-center.

Another trick is to 'feel' for the pressure point when it starts to size - it's pretty subtle (almost a short 'squish'), and requires a fair bit of pull on the press handle....but you can feel it size. I also give the brass a half turn and size it again, just to ensure it's concentric. Note! If you pull too hard, or if your press cams over with a 'snap', you can blow the top cap out of those dies - those aluminum threads are pretty easy to strip.

I also brush the inside of the neck to remove the soot and crud; it seems to me it sizes tighter that way. Last of all, if you want it sized tighter, you can always take the little center 'spud' out of the die and (carefully!) grind it down a hair on a bench grinder.

Lee will also send you an undersized spud, if you need one. I admit those dies can be a bit tricky to get used to, but it's well worth the effort.

I don't know about sizing less than the full neck. I always size the whole neck, and never tried anything else.
 
Crout; I assume you're not refering to the Lee collet die. If in fact it's a conventional die stamped incorrectly as "neck size only" it can sometimes be impossible to neck size only...depending on your chamber dimensions.
Try this: Leave the die out of the press or at least way above the shell holder. Put a case in the shell holder and raise the ram. With the decapping pin retracted so it will NOT decap the case, simply hold the ram at the top of it's stroke and screw the die down until it touches the case mouth. Now lower the ram a bit and turn the die down a turn. Raise the ram again and you should see that the neck has been sized a tiny bit. Repeat until you get the neck sized enough to satisfy. If you go too far try again on a new case after backing the die out a hair or three.:)
Hope this helps.
 
Thanks for the info so far.
I am using the lee collet die.
the press is a rcbs single stage.(no cam over) so at the end of the down stoke i feel the tension then the squeeze(kind of pops). if i turn the die down any more i can't size the case(and actually crushes the sholders on my 223 brass) and if i unscrew a bit no neck sizing happens at all.

i've thought about buffing the mandrel down 0.001 but it wouldn't do any good as i measured the mandrel and then the inside of the case neck after sizing and the difference is still 0.002. shouldn't it be the same size as the mandrel?
BUT...if i take the mandrel out and then size i can adjust how far i size the neck and the neck will then actually grip a bullet.
SO...will taking 0.001 off the mandrel have the same effect?

I actually used to size my old 6.5x55 like that. i broke the pin on the mandrel (made myself a case length gauge and a OAL gauge with it, works great).

But i know the lee die is designed to be used with the mandrel. is taking 0.001 off going to solve my problems and if so why can't I size part of the neck when the mandrel is in?

Sorry for all the questions.
 
Is it possible that the collet has been compressed to the point where it won't let the case in? Sure sounds like it. Take the die apart and stuff in a case by hand, and it should go right up inside the collet with ease. If not you can pry it open easily enough, and don't ever use the die with the mandrel removed. **Also check that the slider that contacts the shell holder is loose enough, and not stuck at the top of its travel.
If you get past this point with isolating the problem it's better to turn the die down less that the instructions say to start. You should never have to exceed one full turn beyond slider contact with the shell holder with the slider fully extended. This is the way the plug gets blown out the end by over-zealous guys.
Get it set up right it'll probably outlast you and your rifle both.:)
 
I have found that you have to use quite a bit more pressure while sizing with a collet die, as opposed to a regular FL die...
 
crout said:
Thanks for the info so far.

i've thought about buffing the mandrel down 0.001 but it wouldn't do any good as i measured the mandrel and then the inside of the case neck after sizing and the difference is still 0.002. shouldn't it be the same size as the mandrel?
Click to expand...

The brass has elasticity, so even though it gets squeezed tight onto the mandrel by the collet, it springs back some after the collet releases it.

Polishing the mandrel down .001 should result in a size difference that remains .002 which will be .001 smaller than before.

Lee says don't take more than .001 off. I think light bullet grip is a common occurrence with these dies.

Above somebody mentioned cleaning the insides of the case necks prior to sizing. This might help a little too.

As for the actual function of the die re. crushing the shoulder etc: I'm not familiar enough with them to comment.
 
Yes if you push too hard you will crush the shoulder back. Are you using .223 or .224 bullets? I use these dies for most caliber I shoot and have had one set since just after they came on the market. I like them so much I had a custom set made for .264 Winmag.
You say the bullets are not being held tightly,can you pull them out with your fingers or press them into the case by hand or are they just seating easily in your die?
 
I use this die quite a bit and love it BUT it is a mechanical die so quite a bit of force is needed to make it work.

I set up the die so that the shellholder hits the die 2/3's down on the lever. This way I can apply some pressure while the lever is 'horizontal'.

I have never found it to matter when the shellholder hits the base of the die. It doesn't affect the end result except the amount of leverage/ease of applying pressure.

The die is such that the shoulder should never get touched. So if you are crushing the shoulders, I would look at the headspace length of your case vs the internal collet length. Make sure there are gaps in all the splines on the collet - these can jam shut.

The collet die sizes the usual 4 thou under so neck tension is really no different then a conventional neck die. The neck interior is not worked so is smooth and seating is easy vs the usual expander ball chatter.

I have yet to find runout created with these dies which is a huge bonus for my match ammo.

They work great.

Jerry
 
mysticplayer said:
I use this die quite a bit and love it BUT it is a mechanical die so quite a bit of force is needed to make it work.

I set up the die so that the shellholder hits the die 2/3's down on the lever. This way I can apply some pressure while the lever is 'horizontal'.

I have never found it to matter when the shellholder hits the base of the die. It doesn't affect the end result except the amount of leverage/ease of applying pressure.

The die is such that the shoulder should never get touched. So if you are crushing the shoulders, I would look at the headspace length of your case vs the internal collet length. Make sure there are gaps in all the splines on the collet - these can jam shut.

The collet die sizes the usual 4 thou under so neck tension is really no different then a conventional neck die. The neck interior is not worked so is smooth and seating is easy vs the usual expander ball chatter.

I have yet to find runout created with these dies which is a huge bonus for my match ammo.

They work great.

Jerry
Click to expand...

Way to go Jerry! When you develope a feel for it your method of setting up the die works great. Trouble is Lee learned the hard way that some guys never develop 'the feel':)and figure more is always better. Thus they blow the plug out of the top and Lee feels obligated to send them a new one.
I'm with you, and think it would be a good idea if Lee included this method in their instruction sheet with the disclaimer "Not intended for the ham handed".
Not a problem for me 'cause I'm down to about 145 pounds, and could sit on the handle without hurting anything.
 
I guess i'll have to shave a thou off the mandrel and see how that works. but i still can't partially size the neck. it's either all or none. and when i do size all the neck it is a bit off force(the manual says 25lbs) and it kind of pops so that's normal and it feels normal.
it's almost as if the collets are too far apart because either the cap is too short, or the collet piece is not long enough. either way i'm not getting enough neck tension and can't no matter how much i adjust the die.

when i do seat the bullets i can push them in by hand a bit into the neck. I haven't seated any with the press because i'm not getting the neck tention i want so why seat a whole bunch of bullets i'll have to pull? the neck tension should be the same as with the FL die, right? the mandrel is the same size so it should have the same neck tension.
 
crout, the top cap needs to be fully tightened on the die body. That should eliminate the popping sound. This die cannot be used to partial neck size but you now know that.

Ensure the fingers of the collet body can move - have a gap and will spring together. If that is working, then you just need to apply force on the press lever to make it work.

If you are using very old brass, the necks may have work hardened enough that they are springing back too much. Neck tension should not be a problem with these dies.

Jerry
 
Neck tension shouldn't be a problem with these dies....

but

It can be expected to be less than with full length dies. It says so right in the instructions. That is also why they tell you how to make the mandrel smaller if you need more tension.

The mandrel being the same size as with FL dies doesn't mean you'll get the same tension. The process is different. With FL dies the neck is made smaller than the mandrel and then the mandrel is pulled through it, so springback is toward a smaller neck.

With the Collet die, the fired neck is squeezed onto the mandrel, so springback is toward a larger neck.

You need to remember that the brass has elasticity.
 
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