To Bump first or expand?

[tonedaddy]

My 6ppc, do you guys bump the should back before you expand the necks from Lapua 220 Russian brass or vice versa. Thanks in advance for your help.

 

[BoydAllen]

Before I wore out a barrel that became my fire forming barrel, (which allowed me to go another way to make brass) I would expand and handle the issue that comes from part of the shoulder becoming the base of the neck, when I turned the neck. I turned the neck so that the angled part of the cutter would make a full cut onto the shoulder, but not so deeply that one could easily catch a fingernail on the end of the cut. This can be set up by trimming before turning and using the step in the turning mandrel as a stop, or it can be done by eye, which is how I did it.

Of course the only place that an expanded and turned .220 Russian case touches the chamber is at the neck shoulder junction, so we are talking about very small adjustments to control fit. If the cut is not sufficient to create a proper fit, and the bolt handle is forced, a doughnut will be the result, which is generally no big deal, given that bullets do not generally get seated into that part of the case, or even near it.

Currently, my preferred method is to expand and turn at .22 caliber to about .011 (for a .262 chamber neck), and then either fire a .22 caliber bullet in the 6mmPPC fire forming barrel with a full case (to the base of the bullet) of any powder that I would use for a 6PPC load.

A variation of this, done with the same turning at .22, is to fill the case to mid shoulder height with Bullseye, and insert a 3/4" square of ordinary kitchen paper towel in the neck (centering it on the neck and pushing it in at its center with a small
Allen wrench) to retain the powder. This is done WITH NO BULLET.

When using a .22 bullet (paired with rifle powder a mentioned), I find that the cheapest 55 gr. FMJ BTs seat surprisingly straight using my Wilson 6PPC seater. I credit the BT for this. Be sure to be close enough to a safe back stop if you try this, since a pattern of indeterminate size will result due to the non fit of the bullet in the bore.

Either of the above methods produce very straight brass, which allows an even cut on the shoulder when they are expanded and turned at 6mm. None of this will negate a missed wind flag reading, or compensate in the slightest way for being out of tune.

 

[SmokinJoe]

Just to add a little; if you aren't too good at making paper wads (like me), just seat an air soft ball pellet on top of that case of Bullseye & fire in an old barrel (NO BULLET). The brass comes out really straight & a little longer than mandrel expanded brass. Then run your 6mm expander in to get the correct fit on the turning mandrel & proceed from there. Also, I recommend doing a FL size on all new brass as a final step before loading, and of course be sure to be checking your headspace so as not to overdo it. You want the brass to have a snug fit in the chamber for fire forming.

 

[Dusty Stevens]

I bump them back before expanding cause if you expand first they wont fit in the die before you turn em and if you turn em before bumping back with varying shoulders your neck turner wont stop in the exact same spot. take that as you will and vary it accordingly. theres a million ways to do it but that method has worked for me for many years and many many pieces of brass with no brass problems in my history