Considering the much slower speed of a heavier conical and that the round balls penetrated sufficiently, there is certainly no advantage to using a conical in this calibre.

Those were the findings of Samuel Baker in India and Africa when used in his double 4. He did have a 'conical' mould made for it, which "led me into such scrapes that I eventually gave up the conical as useless".

Now, we must realize that Baker was using a muzzleloading rifle and in such, had to use pure lead conicals so that'd fit tightly and stay on the powder, however with patched round balls, he could use any hardness of ball, thus the round balls penetrated more deeply than did the conicals.

He also noted that round balls "never failed to floor a charging elephant".

What a round, Bob. Thanks for sharing.