You need to seat deeper and heavy crimp into bullet's crimp groove to prevent bullets from pulling during firing. Speaking of bullets in cylinder not being fired pulling because of violent recoil.
This crimping action will slightly reduce brass dia allowing case to fit chamber.
Your brass is DIRTY - I would never destroy my dies by sizing brass that DIRTY.
OldmanFCSA = "Oldman" at Fifty Caliber Shooters Association www.fcsa.org
2012 & 2013 FCSA Regional Match Director - Alliance, NE - Spring Match June - Fall Match September 2013 - ALL 50BMG Shooters
FCSA Member & SCSA Member & NRA Member & AMA Member
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