conical

Hi all, What are your theories for why historical lead molds included both roundball and conical cutouts? What was the intended purpose of shooting lead roundball out of cap and ball sixguns? Does anyone have supporting documents that write about this? It’s one of those nagging questions now...

I see that .375 and .450 conical molds are readily available for .36 and .44 revolvers, but when I look for a mold or even cast bullets for a .31, I draw a blank. Are there any manufacturers of .31 conical bullet molds that currently produce them or are these special order only type molds?