You mean FMJ bullets? There are plenty for .308, but they're usually 147ish grains. 6.5 Grendel rounds are being sold by Wolf with 100 grain steel jacketed slugs (steel cased as well). Some of the old ivory hunters used 6.5 military rifles with long (really long) heavy for caliber round nose FMJ slugs for elephant due to their great penetration. But, it seems like they're all loaded, or pulled bullets, for military calibers.
But for the grace of God, there, I go.