"the full length sizer leaves a tight fit when i seat the bullet. the collet-sized brass just lets the bullet slide in. hardly any pressure.
i am an RCBS guy, haven't used much lee stuff.."
The Lee collet die is great BUT it does some things most of us are unaccustomed to seeing.
First, FL dies size the neck well below proper neck ID and then the expander rarely re-expands the neck as much as it should be for least bullet run-out. We grow accustomed to that excessive bullet seating pressure so it becomes "right" to us and it does work, in that the ammo goes BOOM. But, any expanding the bullet has to do beyound maybe .002" or so, is irrelivant to actual bullet tension, the brass simply doesn't have that much elasticity so anything more is lost. But, the excess seating pressure tends to push bullets in slant-wise, lost of unneeded runout.
The collet die's mandrel is only a bit less than bullet diameter. After a case is properly sized, and after normal springback, the neck is the correct diameter for proper seating. BUT, as we continue to use our cases the brass becomes work hardened and springback increases, eventually leaving us with insufficent bullet tension. The solution is to get new cases or lap the mandrel down a thousant OR anneal the cases.
Pressing harder on the lever, more than about 20# of pressure, is NOT the solution for more bullet tension. The necks cannot possibly be made smaller than the mandrel so excess lever pressure only has the potential to damage the press or die. In fact, the top cap on that die is aluminum by design so excess pressure will strip out those threads and not damage anything else. It's a good tool.
