Dutch44

Have another think about shaving a few thou of your sizing die. If the issue is your shell bases are not being sized down for your tight Henry chambers and presumably you have the shell holder in the ram bumping the base of the die, then shaving the die will not do a thing for your problem. Shaving the die only helps if the shoulder of a bottle neck case is not being pushed back enough from a stretched case from an oversized chamber.

Your issue appears to be the base portion of the shell in the shell holder is not being sized down as it does not go into the die. On another post our learned friend Von Gruff has the right answer - shave the top of the shell holder thus allowing more of the shell base to enter the die. You only then sacrifice a cheap shell holder without touching the die. This also works for pushing back case shoulders as well. Shaving a die does not alter the die/shell holder interface.

Hopefully you can shave the shell holder down enough without weakening it, to allow case extraction from the sizing die and the case base will be sized down enough to fit your Henry chambers.
If not then your method of forcing the case completely into the die using a pusher shell holder and a dowel to punch the case back out is the only solution to get your case sized down the first time for the Henry chambers.

Hope this is all clear and helps.