I had occasion to change my sizing die the other day. When I checked the depth of the swage, I noticed that I was sizing about 1/2 of the way down to the shoulder. When I screwed the die down a little further, the cases began to lengthen. Is this normal? I know that I am nowhere near the shoulder. How far down should I size the neck?

Also the amount of case creep was about .0015. Is this normal? I thought that the case would stretch only if I sized the neck down too far.

I appreciate any feedback you guys can give me.
EV

The expander button is streching your cases as it pulls back out of the case. Try lubing the inside of your case mouths and see if it helps. How much of the neck you resize shouldn`t make a difference in lenght if you use a neck size die. Full lenght sizing your cases will cause a bit of growth from the brass being displaced when it`s compressed.

Thanks

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Originally posted by El Viejo:
I had occasion to change my sizing die the other day. When I checked the depth of the swage, I noticed that I was sizing about 1/2 of the way down to the shoulder. When I screwed the die down a little further, the cases began to lengthen. Is this normal? I know that I am nowhere near the shoulder. How far down should I size the neck?

Also the amount of case creep was about .0015. Is this normal? I thought that the case would stretch only if I sized the neck down too far.

I appreciate any feedback you guys can give me.
EV

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As the other post states lube in the case neck will help....BUT according to several test done and published in such as Precision Shooting and others the sizing of the body will cause the case to expand in length even without a expander ball in the die.....even if you only size part of the neck in a FL die it will expand the case a small amount...as stated the neck size die doesn't touch the body at all and thus won't make the case lengthen....my limited experience with my cases seems to follow the findings of the authors in the article ...good lube such as the NECO molly/shot kit or Imperial Die wax/lube will help but a true neck die is better....good luck and good shooting!!!

As long as the chamber and the sizing die don't match, cases will stretch.

Think about what is happening to the brass case. It is heat and pressure formed to a chamber. The brass becomes plastic and flows to form to that chamber. Because of the way the case is made, thin on one end and thick on the other, it is held tighter in the forward part of the chamber than in the rear so the front end stays put and the rear end moves back and the brass has to give somewhere.

In other words it gets longer.

Because the rifle chamber is usually larger than the sizing die the case gets squeezed again but this time to a smaller size and the brass has to go somewhere.

The only place it has to go where the pressure is the least is toward the case mouth and the case gets even longer.

Next, you pull a large, hard expander ball through a small brass hole without enough lube and it gets longer still.

You come along and measure it and say, whoa, this case is too long and cut it off. After you do this often enough the case separates just in front of the web.

We call that incipient case head separation.

Now, to combat these effects you need to have a sizing die that is the same size as the chamber and only squeezes the neck down far enough to hold a bullet tight and pushes the shoulder back far enough so the round chambers easy without binding.

A neck sizing die that only pushes the shoulder back a thou or two and squeezes the neck down by 3 or 4 thou smaller than bullet size will work perfectly and your brass will last forever until you get magnumitis and jack the pressures up beyound the elastic limits of the brass and totally wipe out that case and any other case you have loaded that way.

As long as there are manufacturing tolerances in rifle chambers and sizing die chambers we will have to deal with it or have a set of custom dies fitted to a custom rifle chamber or a chambering reamer made to fit your sizing die.

Or, do the cheaper, easy thing and use Redding or Wilson Bushing neck sizer dies, a set of Redding Competition shell holders and set of Stoney head space gauges to measure the fired case and fit the sizing die to your chamber.

A case is tapered and just a little bit of length difference makes a lot of difference in diameter difference.

You can also just turn out your sizing die a little at a time until the cases fit the rifle chamber better, polish down the expander ball so it doesn't pull as hard, polish the inside of the case mouth with Flitz, but that only works for one firing then you have to do it again. Use Imperial or Forster case wax, or not worry about it and just trim to the minimum published size and let it stretch to the maximum published size then trim again.

Lots of things to do and lots of ways to accomplish them. Go back several months on this site and read the posts and you will get a complete education on the vagaries and vicissitudes of the brass case.

This growth you are seeing is normal. What's happening is that your sizer is contacting the case in only two places -- the neck, which is partially resized, and the base. It's the base area that is getting squeezed back down and as a result, unsized portions of the case are being displaced forward. The brass has to go somewhere -- it's just like squeezing dough in your hand. In some cases, cases will grow so long on teh body that the shoulder is moved forward enough that newly sized case won't chamber.

If you adjust your die to make firm contact with your shellholder, and you lube cases correctly as other have suggested, your case growth should lessen a tad. You'll also probably push the shoulder back a bit more than necessary. If you are loading for an auto, I wouldn't worry about it. But if you are loading for a bolt gun you may want to look into Redding's Competition shellholders, which allows you to tailor the amount of sizing based on your rifle's headspace.

Martindog

[This message has been edited by Martindog (edited 05-19-2002).]

Get a set of Lee collet dies and all your problems will go away! No lube, no mess, little effort and cases simply dont grow because they dont use that stupid expander ball idea which appears to be only good for ruining cases.

Andrew,

I have never used nor examined a collet die. Can you explain how they work and why they are better than a " stupid expander ball idea which appears to be only good for ruining cases."

Thanks in advance,

Pete

The collet die works by squeezing the case neck inwards onto a mandrel. There is little vertical force applied to the case and there is no rubbing movement between the case and die, therefore no lube required and no dragging of the case neck. I use collet dies for all my rifles and the ammo they make is far better than that produced by conventional dies, even beating the two sets of "bench rest" die sets I had.

With conventional resizing dies, forster bench rest, my .375 H&H brass was lasting less than 5 reloads because the head space was all over the place, even with the expander button removed. With the collet die cases are lasting well over fifty reloads! The effort to resize a .375 case is less than that needed for .45 acp!

Go with the collet die they are cheap, outperform conventional dies (even the bullet seater) and if they fail to perform as advertised Lee will refund you money.

One tip about the collet die is you can adjust the amount of squeeze applied so you can vary neck tension. Who needs expensive bushing dies? Lee will also custom make a collet die for less than the price of a mass produced conventional die.

Do they work harden the neck?

------------------
Never teach a pig to sing.
It wastes your time and annoys the pig

Andrew,

Thanks for the info; I will give one a try in my .308....

Regards,

Pete

<Do they work harden the neck?>

Anytime brass is cold worked it will work harden. The difference is that with the collet die only the neck is affected and then only once per resizing, whereas with a conventional die the neck is worked twice; first to squeeze it down and then the expander opens it back up. I neck anneal my cases about once every ten reloads. Of course with conventional dies the body and shoulder get pushed around too. Collet dies are a must if you have a rear locking action like a Lee otherwise you will have a head separation after two or three reloads.