If you read about the Civil War, what's striking is how terrible the gunshot wounds were. While other wars had horrific carnage (mostly from industrial-scale killing technology like machine guns, artillery, and bombing), we don't get the repeated, shocked descriptions of the result of small arms fire.
They were so terrible, in fact, that bullets like the Minié ball were banned by the Hague Conventions in 1899. The reason for the destructive impact, and for the ban is understandable if you consider this ammunition to essentially be a .58 caliber (15mm) hollow point round.
You can see the hollow base of most of these, which was one of the key parts of the design. The thin lead walls at the base of bullet were forced outwards by the force of the burning charge. This was the part of the bullet that grabbed the rifling of the barrel, imparting spin to the bullet. The bullet wasn't jacketed, so that the lead could (and did) massively deform under pressure, both at the point of ignition and the point of impact.
Instead of a clean .3 inch exit hole, the wound may have been an inch or more in diameter.
This video compares the results of the Minié ball to modern .30-06 FMJ. The results are illuminating and - if you use some imagination to cast yourself back to Pickett's Charge - horrifying.