My wife grandfather lanced Caribou from his kayak as they crossed the river, his aiming point was behind the last rib, which where the liver would be peirced and no bone struk.
Later, his son , my fatherinlaw used a .22 to the same effect, but with a brain shot.
Today we use a power boat and a .22 , yet al;l at the same site, same caribou, same reasons and same use......now we have speed, in its various forms, in transportation and weapons.
Also, my fatherinlaw taught me that if you have to have a larger target because one of your sights is missing or your vision bad (lost glasses, snow blind, ect) the Liver is a large mid animal target.
If I do, indeed, gut shoot a Caribou or any other animal, I clean it with snow or grass, wiping as much as possible out, and leave the liver for last. I cut the liver and letting them bleed out into the cavity,I place the animal on its back, gut and I wipe the blood around and get out the rest of any moss or chewed vegitation into the inch deep blood in the cavity,, then smoke what I got, have coffee, gas up,........ something to pass 10 minutes, then I tip out the huge clot and all thats in it, that has congeeled while the carcass cooled, and firmed up, and the only sign of a gut shoot is the bullect holes.
As well, the liver, heart, tounge and kindeys make a great hot meal out in the country while hunting