I use 460grain lead conical in my white muzzleloaders and a 300gr spear deep curl or 300gr xtp in crush rib sabot in my omega and NEF muzzle loader . As for lightest 300gr is the lightest I use . Drury brother I like but they get paid to endorse products ,I'd be surprised if they use that light a bullet if not on tv taping .
Can't beat MML forum, great site with no BS.