Lee Collet Neck Die
- Thread starter I Dont Care About You
- Start date
You dont. You apply sufficient force by feel to get the appropriate amount of crush on the neck. An experienced user can tell when the collet has maxed out against the mandrel. This allows you to compensate for variations in neck thickness, bullet dia, brass hardness, etc. If you use the cam over method, you lose this compensating feature.
BTW - Are you using the Hornady 174 gr FMJ boat tails - they could be the source of your problems.
At first I adjusted my collet dies to cam over in my RockChucker. Because the press generates so much force at that point, I never could get the feel of the brass sizing on the mandrel. Now I set the die to size at about 3/4 stroke on the press. You can feel the neck give way and then stop against the mandrel. Is that 25lbs pressure?, maybe. Once you get the feel for it, the collet die is fantastic. I always turn the brass 180 degrees and work it again, probably not necessary but easy to do. As I mentioned before I have reduced most of my mandrels for a bit more neck tension. When seating bullets in brass that was sized in a regular sizing die, I can feel more tension compared to the collet dies. Most of my shooting is done while hunting and that ammunition gets banged around more than target work. I don't want any bullets moving in the cases.
I tried this method and ended up blowing the aluminum retainer cap out. Apparently my 25lbs is a bit more than 25 lbs.
I was using several different bullets and noticed the issue on all.
I am going to order the next smaller sized mandrel which is the one for 308 and see how that goes.
I resorted to using the Lee crimp die to ensure the bullets wouldn't move.
It doesn't have to be exactly 25 lbs but it does need to be enough to size to the mandrel as the die was designed to do.
And neck tension is generally expressed by thousands on a inch of interference fit between a sized neck and bullet diameter, not by force to seat.... like .002 or .004 neck tension
Also, how are you annealing your cases? Are they consistent?
The beauty of sizing to a mandrel is if your annealing is consistent, your neck tension will be consistent.
If you're trying to size between .001- .00whatever by adjusting the depth of your die and cam over you had better make sure your neck thickness is exactly the same on each case and your annealing is exactly the same or you'll be like a dog chasing his tail.
Or you bought a faulty die...I've had that happen with a couple of dies I picked up from Wholesale Sports when they were going out of business.
I'm chalking that up to defective dies being put back on the shelf instead of looking after them properly.
Annealing machine. They are consistent
I measured the mandrel pin. It was what it is supposed to be.
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- Western Manitoba
Page 42 of "Modern Reloading" by Richard Lee - " ... to impress upon you the futility of trying to increase the bullet pull by making the expander ball smaller. If the neck is smaller than .001 inch of bullet diameter, the bullet will stretch the neck to .001 under the bullet diameter." As if he is describing that a case neck has .001" worth of elasticity, and trying to reduce diameter less than that does not increase bullet pull, it "stretches" the brass. He, Richard Lee, is flat out saying that reducing the diameter of the case neck to less than .001" diameter of the bullet, DOES NOT increase bullet pull. Is interesting that his discussion / text is using a diameter to refer to "bullet pull", yet various instructions from the same company (listed in posts above) seem to refer to a weight applied to the press handle??
That occurred to me as well. It is possible the threads in the alum cap were not correct size. I made myself a new cap out of steel. It has the correct threads in it.
Potash - Lee's statement requires some qualification. 1 thou diametral expansion corresponds to 3 thou circumferential expansion. Depending on the caliber, that circumferential expansion represents varying amounts of strain, expressed in inches per inch. Beyond a certain threshold of strain, the material will yield. Once it yields, the neck tension has essentially maxed out. So a larger caliber can accept more diametral expansion than a smaller caliber before yielding occurs.
I think its fair to say that FL dies tend to work the necks more than collet dies. I believe this is purposeful in an attempt to minimize strain induced runout with the collet die. This is quite noticeable if you have a runout gage. FWIW - The stock Lee mandrels are supposed to be 0.002 inches undersize for the nominal bullet diameter. I suppose they only need one thou to work if the bullet is of proper dia, but they add one thou extra to deal with under tolerance bullets.
I think its fair to say that FL dies tend to work the necks more than collet dies. I believe this is purposeful in an attempt to minimize strain induced runout with the collet die. This is quite noticeable if you have a runout gage. FWIW - The stock Lee mandrels are supposed to be 0.002 inches undersize for the nominal bullet diameter. I suppose they only need one thou to work if the bullet is of proper dia, but they add one thou extra to deal with under tolerance bullets.
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On the Lee website in the parts section, the replacement cap for the collet die was listed (in USD) at $4.00, and its currently on sale for $0.00. Since it is designed as the fail-safe release for protecting the collet from being damaged, it might be a good idea to snag a couple while making a custom mandrel order?
Yes. ^^^
And I think the 2 thou is also for counter-acting tenacious spring-back of some hardened brass, for previously well-worked and non-annealed brass, and for some generously sized chambers that blow out the case neck larger.
The cartridges I use Lee collet neck sizing dies for are 30-06, 270 Win and 260 Rem. Annealed or not, I find the neck sizing is more than tight enough with the stock mandrels that came with the dies. In fact after neck sizing, I run the cases through a Sinclair expander mandrel which is 1 thou smaller than nominal bullet diameter, in order to lessen and attempt to even out the neck tension (i.e. widen the neck about 1 thou from the collet dies sizing. This is not necessary for hunting ammo, but I do this for target ammo at the bench for load development, and sporter matches). Even then I can feel some spring back inwards of the case neck mouth as the expander mandrel exits the neck, meaning that the collet die mandrel did its job quite well, and without cam-over force on my Lee Classic Cast breech lock press which does not have a cam-over design. The "25 lb's" is achieved on my press with a little extra push on the press arm on the bottom of the stroke travel.
Yes. ^^^
And I think the 2 thou is also for counter-acting tenacious spring-back of some hardened brass, for previously well-worked and non-annealed brass, and for some generously sized chambers that blow out the case neck larger.
The cartridges I use Lee collet neck sizing dies for are 30-06, 270 Win and 260 Rem. Annealed or not, I find the neck sizing is more than tight enough with the stock mandrels that came with the dies. In fact after neck sizing, I run the cases through a Sinclair expander mandrel which is 1 thou smaller than nominal bullet diameter, in order to lessen and attempt to even out the neck tension (i.e. widen the neck about 1 thou from the collet dies sizing. This is not necessary for hunting ammo, but I do this for target ammo at the bench for load development, and sporter matches). Even then I can feel some spring back inwards of the case neck mouth as the expander mandrel exits the neck, meaning that the collet die mandrel did its job quite well, and without cam-over force on my Lee Classic Cast breech lock press which does not have a cam-over design. The "25 lb's" is achieved on my press with a little extra push on the press arm on the bottom of the stroke travel.
