I would agree that #4 would probably be better then 00 in a 62 .
I would have to disagree with the hopes of improving accuracy though .
Smoothbores can be highly accurate ,in trained hands, at the ranges they were employed.
This issue wouldn’t have been the musket accuracy . But one of weapon efficiency .
What was wanted was as much lead down range as possible when one is volley firing into an apposing force .
Adding buck and ball would have been a force magnifier both at close and longer ranges .
Basicly , with a British single line with a 100 man front being able to volley fire 4 times a minute . 8 times a minute if you deploy a seconding at the ready with both lines advancing upon firing . Thats 800 rounds down range a minute .
Now lets say your facing the same line of an opposing force .A force capable of sustaining the same rate of fire . But instead of loading 1 projectile , they are loading 4 .
That’s 1600 rounds down range per line, per minute . X 2 if the second line is at the ready and advancing . Thus you have 3200 rounds going into the opposing forces direction per minute .
Even if one was to claim that a 00 ball wouldn’t remove a soldier from the field . The wound ,if it did not kill them , would still effectively reduce his combat efficiency . IE ability to reload . Thus over all reducing the efficiency of the unit as a whole .
Then when you add in the shock an aww factor. IE the realization within the opposing force that 4X the amount of projectiles would be coming their way .
At closer ranges this would have been even more devastating considering the chances of surviving such a mass fire would have been far less .
Anyway , just a thought