Posted by Michael Bell on
URL: http://oldforum.flyshooter.com.au/Setting-up-your-dies-correctly-tp5707744p5707792.html

  It is possible to size cases with "reasonable" accuracy without using shoulder bump gauges, callipers or indicators of any kind.
It wasn't until I acquired a 2nd hand 6 PPC and then bought dies which came with a "bump" gauge that I knew what such a gauge even looked like….I actually had no idea what this thing was until I accidentally fell across an article, with pictures, which explained it's use….
If you don't have bump gauges or indicators you will need to go by "feel".
The object of the exercise is to size your cases by the smallest amount possible to achieve bolt closure with minimal pressure.
It's best to remove the firing pin because a reasonable amount of the tension you feel when closing the bolt is because of the cocking of the firing pin.
If you can't or don't know how to remove your firing pin you must be aware of the tension needed to close the bolt WITHOUT a case in the chamber.
Simply close your eyes and close the bolt multiple times "feeling" how much pressure is required. Then insert a fired case and do the same…closing the bolt with your eyes closed while "feeling" the tension…usually it will require more pressure to close when a fired case is in the chamber because the shoulder of the case is in firm contact with the shoulder of the chamber in the barrel.

If you are able to remove the firing pin you will notice the bolt handle will fall, with no effort required, to the closed position when inserted into the action (with no case in the chamber). Now insert a fired case into the chamber and close the bolt…if the bolt still falls to the closed position without effort the case is probably undersized. If it requires a lot of effort to close the bolt then the case definitely requires sizing as the pressure you are feeling is the case shoulder being pushed into the chamber shoulder.

You must now set up your full length die so that it sizes the cases allowing the closing of the bolt with the tiniest amount of additional pressure. You could wind you die so that it just touches the case holder and then wind it out a good half turn or so. Select a case that is difficult to close the bolt on and size it in the die. Insert the sized case in the barrel chamber and try to close the bolt.If it is still difficult to close you will need wind the die in a fraction further. You might need to repeat this process 5-6 times winding the die in tiny bit by tiny bit until finally the case shoulder has been moved enough for the case to be inserted into the barrel chamber and the bolt closed with minimal pressure.

This not the best method..I now use bump gauges to measure the amount of set back and find it much more comforting to know for sure how much resizing is actually happening but I can say that old method I used for years was still pretty accurate.

Regards,
Belly