It's because leather stretches to whatever diameter you push into it - .303 tapers from .460" at the rim to .401" at the shoulder,
7-08 is .470" at the rim to .454" at the shoulder (based on a quick google search). You cannot move down in diameter from 7-08 to .303 and expect it to hold tight, you could go up from 7-08 to 7mm mag and it would work just fine.
True story, start em small an move them onto bigger Cartridges as she loosens up! it was Not leather but the Elastic material ones.
wise man Ndallyn




















































