Posted by Nick Aagren on
URL: http://oldforum.flyshooter.com.au/Setting-up-your-dies-correctly-tp5707744p5707752.html

I guess we're all doing it or should be doing it, setting up our full length sizing dies for correct head space that is, but I think  it would also be worth going over why we are doing it?

I was taught that it is preferable to full length size cases after each firing to ensure that I didn't get a case that was difficult to eject while in the middle of shooting for record. And that adjusting for minimal (.001-.002) head space increases the life of the cases while also allowing the bolt to be closed without too much force.

So my understanding is that setting up sizing dies correctly will not have an affect on shooting small groups in itself but let's say if a case gets stuck from not full length sizing or sufficient head space bump and I've got no sighters left with one or two record shots to go. If the wind changes before I can eject the case then the chances of shooting a small group are reduced because the momentum of the string of shots has been interrupted and a new set of wind conditions are in play.

I use a set of Redding competition shell holders and a head space bump gauge with calipers to measure the shoulder set back. I also close the bolt on a sized case to feel how easily the bolt closes.

I'm interested to hear others thoughts.