GaryDoo7,
Try sizing the cases without the expander being installed.Normally a sizing die oversizes the neck and then when the extractor is withdrawn it expands the neck to some predetermined size.By removing the expander, the initial sizing might be enough to hold the bullet.If you use cast bullets,they should be .002-.003" over groove size which would also help.If this still doesn't work, you can go to sizing just the neck by running the case into a 41mag(or other avaliable die)sizing die.If you haven't bought the 10.3 dies yet, you should do so at that price, even with the slight mismatch of bullet dia.
Mike
