If anyone chooses a shotgun......be very conscious that all slugs arenot created equal. The old standard sugs of yesteryear will likely fail miserably! They are very soft lead, starting out with a huge frontal area, expanding very rapidly upon impact.....penetration will be almost non-existent!
If a big-bore lever gun (as in 45-70 with a .459” dia. bullet) is considered lethal....perhaps my 5 - shooter moving a .452” dia. , 400 grain, hard cast, wide metplat, bullets @ near 1600 fps mv will also be adequate! Easier to handle in very close quarters, and capable (though a handful) of rapid shots with one hand.....not real easy to do with a shotgun or a lever gun! Can also reside fairly comfortably in a cross-chest rig, leaving both hands for camp chores or fishing while being quite adequately armed!
But hey......that’s just me!

memtb