Originally Posted by
PipIstrelle
It makes absolute sense .
A full length die sizes in the order of , outside neck diameter, body /web , shoulder then inside neck diameter. If the die squeezes the body before the shoulder engages the case will grow in length. Similar to squeezing a balloon. It's quite a common phenomena and quite possibly effects some dies more than others , both my 243 and 223 hornady dies will do this my 6.5 Creedmoor, Forster bump die won't , probably because it's not designed to body size .
Just a quick example , I use Redding competition shellholders, I use them because it's easier to achieve consistent sizing . Sizing fired 243 cases and using the +0.010" shellholder the cases grew by 0.001 to 0.002 " , using the +0.008" the shoulder would remain pretty much as were and the +0.006" shellholder gave a consistent shoulder set back of 1 to 2 thou" . All measurable and the cases sized with the +0.010" were difficult to chamber . The growth occurs in the head to shoulder measurement.
I anneal, so none of the case growth can be attributed to spring back .
I'm really surprised you haven’t come across this , it seems to be a recurring question on The Stalking Directory forum . Sometimes it can be attributable to the dies or shellholder, generally it appears to be poor die set up .