Here's an approximation of the 6mm Niemiller beside, L to R.  A once fired and unsized .243 case with a Eagan MX2-243 bullet sitting in it.  Next a full length sized .243 case, then the Niemiller.  It's an approximation cause the expander rod would need to be modified a little too and I'm not doing that yet.  The shoulder has another .010" to go, but the rod is about the same length as the the case body and I'd be pushing the rod up into the neck while the case is still in the sizing die.  I already blunted the depriming pin pushing the case up into the die this far. 

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