Can someone help me with partial resizing!!

[uad7116]

I have been reloading for awhile and understand the concept of partial resizing but don't completely understand how to adjust my dies to accomplish it. I am resizing my .338-06 brass with a set of lee dies and they don't offer a neck sizing die without custom making one and I'm try to just bump the shoulders back on my fired brass .001-.002 or if I can just size the neck? So can someone please help. Thanks Kris

[Fjold]

Back your full length sizing out one full turn and size a case. Try this sized case in your gun and the bolt should not close all the way. Turn your die in 1/16th of a turn at a time until your bolt just closes. This will size your cases to just fit your chamber.

[Elkbane]

If you bump the shoulders back at all, you'r not really partial sizing - you're really sizing for minimum brass distrubance, which is what your goal should be.

He'res what happens when you size: The sidewalls of the brass hit the die sidewalls first and the brass is compressed inwards. Brass being somewhat elastic, this actually moved the shoulder FORWARD (the casehead is held fixed by the ram/shellholder and the brass has to move somewhere). Then, depending on how "deep" you have your die screwed in, the shoulder of the brass comes in contact with the die shoulder and bumps the shoulder back. You'll need a way to measure the headspace (length from casehead to datum line at mid-shoulder) to make proper adjustment of the die. Either a stoney point tool on your caliper or a 38special/357 case slipped over the neck.

First measurement is on a fired, deprimed case. Measure casehead to shoulder datum line.
Next, measure a sized case the same way.

Adjust your die in or out until the difference is about a thousands. That will give you just a little "feel" on the bottom third of the bolt throw when you close the bolt on a loaded round. It takes some minute adjsutments of the die depth to get it just right, but it's worth the effort.

If you want to partial size, back the die out a turn, but be aware that it can make your cases longer and be a little difficult to close the bolt as poster above indicated.
Elkbane