Tonight I was setting the shoulder back on my once fired Fed 308 cases.I believe they started out at 1.622 new and grew from 1.625 to 1.627. This is my first time doing this so I figured that I would bump the shoulder to 1.625. Once I set up the die I figured that all would come out at the same length. As I was adjusting the die some actually got longer and after further adjustment I would say that 90% came out at the desired length and the others were off .0005 to .001. The press is a coax and this is for a 308. Just not sure why the set die doesn't set all the cases the same.
Shepheard, There is always going to be some variation and yours might be about right for your brass. The one thing I have used to help reduce the resizing variation with my 308 brass is the Redding Competition Shellholders. The Plus 6 shellholder does the trick for my brass and chamber. What makes the shellholder work so great in my case is that you can prepload the press force on the shellholder which takes the any spring factor out of the press and any differences in the brass. Just screw the die down on top ram when at top dead center and tighten hard or adjust down more by backing the ram down and feeling the force by raising the ram up again. The best thing about using these shellholders, is the next time. Just use the same shellholder tighten down hard and everything comes out the same as the last time.
The cases lengthen headspace because you are "squirting" the case forward in the die and not actually bumping the shoulder yet. Screwing the die IN should have started bumping back the shoulder. JB
Another reason for the variance in sizing is the slop in the threads of the die and press. Try this, leave the locking ring of your die loose. Adjust your die for the correct bump. Now turn the sizing die down another 1/16th turn. Run a case into the die, keep pressure on the press handle and tighten up the die locking ring. This will take the "slop" out of the die and press threads. I think this will help you a lot Jim
