I have a problem forming 223 brass to 7TCU. I went through about 300 pieces of 223 brass looking for the longest cases I had. the shortest case I segregated was 1.754" the longest I had was 1.77".
I did a 1 step process running the 223 brass into my RCBS 7TCU sizing die. The trimmed length is supposed to be 1.75" for the TCU case. I lubed each case inside the neck before re-sizing.
The shortest of the resized cases was 1.73? and the longest was 1.74?.
is there a way when reforming to lessen case shrinkage? Kevin