The .44-40 at relatively short range would do it if the targets were close together. The .45-70 rifle round would definitely do it. The little .31s and short .38s or muzzle loading .36s would be much less likely to.
If we're talking modern v late 19th C handgun bullets, here's a comparison chart.
.31=.32acp
.36/.38S&W=.38spl target load
.38-40=.40S&W
.44-40=.44spl
.45 Colt/.45Sch=.45acp
For instance, the modern .40S&W fires a bullet of the same weight and diameter at the same speed as the standard load of the .38-40, making them virtually identical ballistically.
Some of the older rounds don't have directly corresponding modern versions, and some -- notably the .45 colt have evolved well beyond their original potency due to the availability of modern brass and firearms that will handle the pressure of hotter loads.
Note also that a given cartridge loaded in a rifle will be more powerful because of the extra burn time in the barrel. Also that not all calibers were available in rifle format.
Dedicated rifle rounds of the era might only barely slow on their way through the first target. Think .45-70, .45-90. .50-110. I believe it was a .50-90 that knocked a Sioux chief off his horse at a measured 1,538 yards at Adobe Walls in 1874. Think of what such a shot would do at lesser ranges. As another example, when the U.S. Army was testing the trapdoor Springfield rifle, they found that the bullet, at more than 1200 yards, would completely penetrate 2 rough cut oak boards 1 inch apart. Rough cut, or pre-planed boards are 'true measure', which means that 2 inches is 2 inches rather than the 1 1/2 inch 2 inch boards you commonly find at the home improvement store.
TL;DR, the .45-70, which was common as dirt, had roughly the muzzle energy of a modern day AK47, but with a projectile more than twice as heavy.
Yes, I did a truly demented amount of research on this subject for one of my own projects.
ETA:Regarding your Winchester '73. A .44wcf (.44-40) out of the typical rifle barrel would have slightly less power than a factory 240 grain .44 magnum out of a 6 inch barrel. You'd have to be careful not to kill both characters A and B.