Well, considering the whitetail deer and Elk populations as well as the Bison population were nearly wiped out to extinction with pure lead bullets as well as cup and core, I see no real reason for them myself other than money makers. Now granted, some of the newer designs for muzzleloading bullets such as the Lehigh Controlled Fracturing bullet has a real use because you want to create as much internal damage as possible since you only have one shot for the most part, many of these new monolithic armor piercing rounds are just absolutely NOT needed for the simple hunting that we hunters need. You put an old cup and core bullet where it's SUPPOSED to go and you will have a dead animal. Simple as that. I honestly have no clue how many deer, hog's (I do know my Elk numbers) and many other big game animals I have taken over the years with Corelokt, and Hornady Interlocks and Interbonds. Not to mention the whitetails taken with hand made connies out of my muzzleloaders. Or the jacketed lead slugs for my shotguns.