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Tried all that plus a few things on youtube. Contacted Lee this afternoon and asked the question they said I need to give it more oomph when pressing down on the press handle. Will give it a go.

On the dummy rounds I was getting I could just about wiggle the bullet home with some resistance.

MikeB

You need a RCBS neck die problem solved. Or a set of full length dies to play with until you become more familiar with the dark art. Or a fellow shooter in your neck of the woods to help you out.

Somebody in South Wales to teach me the ways of the 'force' (the force being that applied to the rockchucker lever! :-) ....... good suggestion.

Just worried that I might damage something by over stressing the die ...or the operator!

I have the Lee full size die as well but this significantly changes the .303 brass and would probably kill the life of the case.

I will have to have an experiment....

MikeyB

When you have resized the case can you see four equidistant vertical "ribs" on the neck of the case?

Also had this from the Lee Precision customer service guys....

On a Rock Chucker press the proper installation of the die is two full turns past contact with the shell holder. This will keep your press from camming over. If the press cams over the die will be damaged.

The ideal case neck ID for a .311 bullet is .310". The tensile memory of a brass case neck of normal thickness is about .001". This value can vary a little dependent on the hardness of the brass and its thickness. But normally here is why .001" under the bullet diameter is the best diameter for a case neck ID. If you press the .311" bullet into the .310" case neck and then pull the bullet and measure the neck ID it will be .310". If you sized the case neck ID down to .308" and then seated and pulled the .311" bullet the case neck would measure .310". The brass maintians the .001" spring back and that is what gives the seating tension. Going below the .001" under invites bullet run out. Bullet run out is caused by the thicker snd stronger side of the case pushing the bullet to the thinner weaker side of the case when the bullet is seated. If you keep the case neck expansion to the .001" when seating the bullet the tensile memory of the brass is not exceeded and run out is minimized.

Thanks,


Peter
Customer Service



I did get a few ribs down the case mouth. The issue is that the dimensions that Lee are quoting (.001 under), I can still wiggle the bullet home by hand, granted with some pushing and shoving...

You could try annealing half a dozen or so to see if that makes a difference or try a different batch of brass.

If you are getting definite ribs then you are sizing them well.

BTW, what is the ID of the sized case neck?

Have you measured the bullets and checked that they are .311"?

To night I selected half a dozen privi once fired cases. I selected six bullets and measured them. They are .311.
I inserted a shell holder in my Lyman orange crusher press. I raised the ram so it was at its highest level with the handle fully cammed over. I then screwed a Lee collet neck die in until it just touched the shell holder. I lowered the ram then screwed the die in two full turns.
I inserted the bullets in to the un sized cases they went in easily.
I then ran the cases through the die until it bottomed out on the shell holder and gave the press handle a bit of force . I then tried the bullets in the cases I could not push them in by hand and when seated they were good and tight. I did the standard test and pushed them in to my re loading bench top and they are fine. Good to go.
Don't know were you are going wrong my friend are you sure your bullets are .311.

Right then. Screwed the Lee die into the Rockchucker until it touched the shell holder. Lowered the ram and then screwed the die in half a turn more. Not one full turn or indeed the two full turns it recommends in the manual for cam over presses but only half a turn.

If I put in a once fired Privi .303 case and then raise the ram the primer pops out and then the arm comes to its pre-cam over point. With light pressure the cam then locks over and comes to the end of its travel. The case then exhibits the slight lines down the neck where it has been squeezed by the collet and they measure on average .308.5 - .309 inside diam.

The Privi 174g bullets do vary by the box but I have selected a batch that are indeed .311 in diam. The bullet then feels tight and is very difficult to try and push them in by hand.

It says in the leaflet that if you set up the press like this then you will damage the die in a cam-over press??? I noticed that somebody else was doing this as well.

This has seemed to work better for me than the full two turn instruction and lots of force on the handle method. Ran 20 once fired cases using the half a turn method and they all seemed pretty good.

Mike

dromia wrote:
Is the collet and sleeve lightly grease where they meet?

Did you intend to post that on Ann Summers' website, ooman ?