Its not unusual to see that difference in length. Your dealing with a 30 cal from what i'm reading and the pressures are pretty high on the press and dies.
Just be careful on your core seating pressures/ It looks like lube also is having an effect on your final length.
Try some anhydrous lanolin for your lube and use a bit extra to see what happens. I think your not useing quite enough.
Tool steel dies will do this quite a bit more then carbide dies.
You can opt to have a carbide point die made, that should help
Sorting bullets is really a good idea for match shooting but for practice it may not matter as much.
I hope this help you out some and your problems get fewer.
PS I hope you have a good press also, you may be getting some spring back
Just be careful on your core seating pressures/ It looks like lube also is having an effect on your final length.
Try some anhydrous lanolin for your lube and use a bit extra to see what happens. I think your not useing quite enough.
Tool steel dies will do this quite a bit more then carbide dies.
You can opt to have a carbide point die made, that should help
Sorting bullets is really a good idea for match shooting but for practice it may not matter as much.
I hope this help you out some and your problems get fewer.
PS I hope you have a good press also, you may be getting some spring back