I'm having a problem with my 7STW cases or??? I'm using Winchester brass and the cases don't seem to be gripping the bullets tight enough. I can push them into the case with pressure from my fingers. They don't just drop in easily, but I am a little concerned they will shift under recoil in the mag. I'm using Redding dies. A virgin, neck sized round measures .308-.309", a fired/neck sized is .309, neck sized/loaded is .310" I do not feel the expander ball exit the case-no resistance whatsoever. With the expander ball removed, I get the same measurements as listed above. I have only recently started noticing this and I've had the rifle since 1996 and the dies since about 1999-2000.