Assuming they got it all back......how likely is that?
Quite likely. The lead they used was fairly soft, and held together well at the low velocities.
Moreso if they used copper balls, like the Mexicans did,
Mexicans of the day commonly used copper? First I heard of this one.. Copper was more plentiful than lead down there?
much less so if they used lead. That ball would have had to strike nothing but soft tissue on every hit, not to have been badly deformed and fragmented. Occam's razor.
The 'razor' of soft lead & fairly low MV's would make it rather easy to recover bullets.. Even ones that struck bone.
But 40 times? Granted, the bull was probably being slung, & more than a bit..
Yes. They used copper balls in their smoothbore muskets during the 1836 campaign. I don't know why, but their use of copper for bullet material is documented. It would have accelerated to higher MV's, but given the poor accuracy of smoothbores, I don't know what the advantage would have been.