Lee Collet dies and neck consitency

[10at6]

I've used Lee collet dies for years and have notes. One thing I have noticed is that run out is reduced, but also the variation in neck thickness was also reduced. I have had it on my mind if someone built a better, more precision version of the collet die if it might not be a viable alternative to neck turning?
When I use the collet dies I turn the cases 3-4 times in the shell holder.
I'm thinking the brass flows a bit under compression, thus the results.

Just thinking outside the box. But the Lee collet dies do improve variation in neck thickness IMO.
Thoughts?

 

[Rocketvapor]

You are probably flattening surface irregularities.
I doubt the brass is flowing under collet die pressure.
Might be though.

 

[Mikemci]

It probably does. I'll have to measure my case length, before and after. Seems like the brass would flow to the top of the neck.
Also check neck thickness at 3 or 4 points. Thanks, I never considered the possiblity.
You never know, until you measure.

 

[Rocketvapor]

It does have to go somewhere

 

[10at6]

Perhaps. But the neck run is reduced w/o question. It's hard to measure neck thickness given the tiny ridges the collet die makes. I don't neck turn. But what I have seen is a reduction in neck thickness variation on good brass.
Having a custom Lee collet made for my 6 BRA no turn neck. On my Lapau cases thickness does not vary much

 

[Uncle Mike]

I have thought just recently why not make a die to squeeze the neck on an appropriate size mandrel to correct uneven neck thickness and then proceed with proper bushing die before seating bullet. Looks like Lee has already done it in only one step, maybe.

 

[Mikemci]

I don't get ridges. I do like 10at6 and rotate the brass 120* and run each piece 3 times through the die. The ah-ha moment for me, was setting up the die, per John Valentine's method.

 

[10at6]

Nor do I really. I use a cam over for consistency. Just saying I have found neck thickness to vary less after collet sizing

 

[Mikemci]

Nor do I really. I use a cam over for consistency. Just saying I have found neck thickness to vary less after collet sizing

The cam over setting is what I was referring to. It solved all of my issues with this die.
I've just never thought to take measurements for brass flow possibilities. I will next time, just out of curiosity.

 

[gman47564]

I have used the lee collet dies for a good while now and in my opinion if the collet is leaving ridges on the neck your squezzing the collet too hard... back your die out till them ridges are gone and it will still size the necks … big fan of the lcd….

 

[bozo699]

Nor do I really. I use a cam over for consistency. Just saying I have found neck thickness to vary less after collet sizing

well I’m not going to argue or being a butt but.. your not suppose to use a Lee collet die by camming over. On presses that toggle your suppose to run die down two full turns so press can’t toggle and possibly damage the die.
Wayne

 

[Mikemci]

I'm not going to argue with you either.
I do have a question, though, how do you know how much pressure to put on your press handle, to get consistant pressure on the neck?
That is how guys get ridges on one neck and not on the next one.

 

[Homerange]

well I’m not going to argue or being a butt but.. your not suppose to use a Lee collet die by camming over. On presses that toggle your suppose to run die down two full turns so press can’t toggle and possibly damage the die.
Wayne

Despite Lee's instructions of how to set the LCD a recognised alternative is the Valentine method that does use cam over and his method's primary advantage is to obtain more consistent neck tension.

I use both methods depending on which caliber I'm loading.

 

[gman47564]

cam over the press and keep backing that die out till it quits leaving them vertical ridges that you can feel with your thumbnail and you will get very good results out of the lcd...

 

[bozo699]

I'm not going to argue with you either.
I do have a question, though, how do you know how much pressure to put on your press handle, to get consistant pressure on the neck?
That is how guys get ridges on one neck and not on the next one.

I haven’t used collet does in a number of years but when I did I used a lee cast press , a adapter on the handle and 25 foot lbs if memory serves with a 1\2” drive torque wrench.
Wayne

 

[Iowa Fox]

I've used Lee collet dies for years and have notes. One thing I have noticed is that run out is reduced, but also the variation in neck thickness was also reduced. I have had it on my mind if someone built a better, more precision version of the collet die if it might not be a viable alternative to neck turning?
When I use the collet dies I turn the cases 3-4 times in the shell holder.
I'm thinking the brass flows a bit under compression, thus the results.

Just thinking outside the box. But the Lee collet dies do improve variation in neck thickness IMO.
Thoughts?

Your absolutely correct on both counts. If you can see squeeze lines on the neck you are squeezing to hard. Google John Valentines instructions on here, after I read them is when I started to get the most out of my collet dies..

 

[Texas10]

Brass wil definitely flow when squeezed too hard in the collet die. That is evidenced by the "squeeze lines" left in the neck. I back off the die until there are no ridges left after sizing, and also rotate during sizing. Measured runout is nil and neck wall thickness variation is within .0005 to .001, so I too believe there is some reforming going on.

I have noticed that unless I anneal often, as the brass work hardens in the neck it springs back a goodly amount after sizing. After the 8th or 9th cycle through the gun and die, the brass spring back is such that my measured neck diameter before and after seating the bullet differs by as little as .0005 (five ten thousandths of an inch). Neck tension is still good and fairly consistent but I can feel the difference while seating a bullet as opposed to a freshly annealed neck.

This is in a no neck turn Criterion barrel, not throated long for heavies. YMMV.

 

[PopCharlie]

Perhaps. But the neck run is reduced w/o question. It's hard to measure neck thickness given the tiny ridges the collet die makes. I don't neck turn. But what I have seen is a reduction in neck thickness variation on good brass.
Having a custom Lee collet made for my 6 BRA no turn neck. On my Lapau cases thickness does not vary much

I kept reading great things about these dies. So, I had custom Lee collet dies made for my 6mm br and 6.5x47 Lapua. I stopped using them because I could not get consistent adequate neck tension without the collet imprinting the little ridges on the necks. Measuring neck wall thickness variations and run out can't be done accurately once the necks have been imprinted. I experimented with the seater that Lee sends with the custom die set. I stopped using them too due to horrible run out ( measured at the bullet ogive). I was getting .005 or more. I ended up trashing the brass and going back to my Whidden dies.

 

[T-shooter]

I kept reading great things about these dies. So, I had custom Lee collet dies made for my 6mm br and 6.5x47 Lapua. I stopped using them because I could not get consistent adequate neck tension without the collet imprinting the little ridges on the necks. Measuring neck wall thickness variations and run out can't be done accurately once the necks have been imprinted. I experimented with the seater that Lee sends with the custom die set. I stopped using them too due to horrible run out ( measured at the bullet ogive). I was getting .005 or more. I ended up trashing the brass and going back to my Whidden dies.

Have you tried polishing the central mandrel down to increase the constriction and tension without using too much pressure?

 

[dolek]

I kept reading great things about these dies. So, I had custom Lee collet dies made for my 6mm br and 6.5x47 Lapua. I stopped using them because I could not get consistent adequate neck tension without the collet imprinting the little ridges on the necks. Measuring neck wall thickness variations and run out can't be done accurately once the necks have been imprinted. I experimented with the seater that Lee sends with the custom die set. I stopped using them too due to horrible run out ( measured at the bullet ogive). I was getting .005 or more. I ended up trashing the brass and going back to my Whidden dies.

If you are cranking hard enough to make ridges you need a smaller mandrel.