In the 1800's when dealing with dangerous game, the hardened round ball in muzzleloading guns ruled supreme. The early breech loading systems were not strong enough, thus not powerful enough for dangerous game. Since muzzle loaded conical projectiles had to be pure or almost pure lead, thus they lacked the penetration required for killing heavy dangerous game due to their almost instant expansion reducing penetration.
That is why round balls (hardened) ruled into the 1880's, with larger and larger bored guns - 4 bore being the larges I have heard of. Baker himself had a conical mould made for his 4 bore double, with a short 3 bore weight of conical ball, thus 2,333grains, but of course, it had to be soft lead and thus lacked penetration on elephant. He noted this bullet led him into such 'scrapes' that he eventually gave up the conical ball as being useless in killing dangerous game - with a muzzleloading rifle.
Once the stronger breech loaders were developed, a hardened smaller diameter bullet could be used, giving sufficient penetration to dispatch those dangerous fellows.
