You're trying me, "I raised my shellholder and lower my dies to touch it snug."
You've done that over and over. Yet, your cases will not chamber with your method. Try adding the following to your method. "Now lower the shellholder and then turn the die in an additional 1/8,1/4, or more turns past snug." Try that for something different. It'll chamber if sized right.
keep more if necessary. What kind of press are you using?