LEE's Neck Sizing Dies

[Sagetown]

What makes the Die resize the case neck?

I went through the instructions 3 times and got nothing. Then I took a pair of pliers and cranked hard on that knurled knob at the top of the Die.

After that I got a fairly tight neck size that would not let the bullet fall into the case. Is that knob the secret?

 

[Bad Flynch]

I take it that you are referring to Lee's Collet-style sizing die. It is the compression of the collet that causes the fingers to close on the case neck and squeeze it against the mandrel, thus sizing the case neck.

The knurled knob on the top is not the proper adjustment; one must compress the collet extension that sticks out of the bottom of the die body. This is accomplished by screwing the whole die further into the press so that the shell holder moves the collet insert when the ram is at top dead center.

The adjustment of the die can be tricky when using the die in a press whose linkage allows the ram to travel beyond top dead center. However, it can be accomplished and, once adjusted properly, works quite well.

 

[ranger335v]

There is a learning curve but it's a fine neck die.

The knob at the top is simply a screw that retains the sizing collet and mandrel/decap pin in the body. It need be no more than finger tight and is not considered an adjustment, as such.

If you lube the inner sleeve's upper end, the collet fingers, with a light coat of grease and then turn the die body down in the press enough it will work fine.

 

[Sagetown]

I'll re-adjust the Die again and start over. I was stopping the down stroke when the Ram made contact with the Die.

If I'm understanding you men correctly ~
What I should be doing is putting more pressure on the Ram at the end of the stroke to activate the collet. Thus, by turning the Die down into the Press will adjust the collet to properly size the neck . Hope I got that right.

 

[K3]

A good way to check is to take a bullet and see how it fits into the sized case. It shouldn't go in by hand. Then compare that to a fired, unsized case. The bullet can pretty much fall into the case there. Note the difference.

At the end of the stroke, I give it a good amount of pressure so that the collets do their work. If you stoppushing at the initial contact or when the case is decapped, you will not size the neck correctly or at all.

Occasionally you will get a Lee neck die that has a mandrel that needs a little polishing. I had that problem on my .270 die. I didn't have enough neck tension on the bullets. I was pressing hard in the lever, but results were not good. I chucked the mandrel in a drill, took some 600 grit paper, and I took a couple of thousandths off. Now it works great.

 

[Sagetown]

K3; I'll check into that about the mandrel because like you, I thought I was giving adequate pressure, but with no results. With y'alls help maybe I can get things running.

Thanks