re: Barnes, I don't think he was wrong in his measurement of "bullet dia" at 0.439". BUT they were patched, double wrap, which brings the "PROJECTILE DIA " up about 10 thou's to about 0.448". All of our lives would be better if Barnes OR all the die makers had taken that into account. Then we would have gotton usable necking tools first time round. It's a pet peeve of mine.
rmcc- should you do a chamber casting, you may want to pull the block out first. don't ask me why