With the .308 any cup & core will do. The .257 will require gay, mono-metal, & expensive bullets.
But have if you're into wasting money to get the jod done the .257 may be for you.
Yep, those Hornady Interlock bullets sure are expensive...
Yep, I hear ya...I believe they were all of about $16.oo for a hundred count box, last time I looked...good thing folks like'em for puttin deer down quick..may not sell'em otherwise
