I am going to try using an expander mandrel for the first time and I'm still new to reloading. I did a search in this forum and found a lot of good info. However, when someone asked: "The expander mandrel is the last step before seating the bullet?" and the reply was "Yes", that made me wonder whether I should take that statement literally since that didn't make sense to me. Wouldn't that be difficult with powder in the case since otherwise that would be the last step before seating?.
I have some primed brass and would like to use the expander (before proceeding with adding powder). Could there be pressure build-up when using the expander mandrel since the case is 'sealed' with the primer in place and wouldn't the mandrel actually create an air tight seal at the neck at the same time? Could that either cause the primer to pop out or loosen, and/or cause the case to bulge out?
I have some primed brass and would like to use the expander (before proceeding with adding powder). Could there be pressure build-up when using the expander mandrel since the case is 'sealed' with the primer in place and wouldn't the mandrel actually create an air tight seal at the neck at the same time? Could that either cause the primer to pop out or loosen, and/or cause the case to bulge out?