Ropinfool you need to attend the Dan Boone school of BP rifles.
The soft lead ball fired from a ML rifle will double in size on big game animals. The reason the big slow lead balls were so deadly is that smash and mash.
The high velocty bullet can hold together and deliver heavy shock. The .338 and other heavy rifles kill with out rapid expansion. The reason small bullets must expand is to deliver big bullet shock. The problem is the small bullet will due to the hydraulic effect do more tissue damage. There is a reason that the .338 is so popular with many western hunters.