case head separation on TC's loaded hot & then full length sized a few times is a fairly common occurrence.
kind of a catch-22 scenario, when loaded up to max pressures, case head expansion is such that it becaomes becessary to FL ressize, but in doing so, bumping the shoulder back causes headspace issues, resulting in stretch. after a few firings, you pull out half the brass....and contenders dont lock up like a vault anyway.
for contender cartridges that walk the line on pressure, i try to neck size, and when necessary to body size to reduce case head dimensions, i do so with a straight wall die...in otherwords, when sizing the 30/30AI, .25/35AI, etc, when necessary i use my .375win die for bodies, and my 358jdj, 375jdj, etc get sized back with a 444 die.
body OD at the case head on the SuperBower cartridges can also be bumped back with a .444 FL die. worked like a charm on my 307/356.
by neck sizing when possible, and keeping load pressures to sensible levels, you wont get many head separations.
the collpased shoulder looks kind of like a lube dent to me maybe, maybe from a case that was just sized?
Last edited by FyrepowrX; 02/12/12.
