This was my method for making 17FB from 221. Run the case into the 221 sizing die with the expander removed this reduces the neck to the smallest diameter possible with my equipment. Then run the case into the 17FB seating die with seating stem removed and finally into the full length 17FB sizing die. Still lost a few cases especially if I hurried the process a little. Since that time I purchased a 20 Vartarg rifle and now use the 20VT sizing die as an intermediate die and case loss has been zip. Without the 20VT die I would be tempted to buy a used set of 204 Ruger dies and shorten the sizing die to use as the intermediate die,
