The inline muzzleloader and its .50 cal polymer tip sabot bullets seem to do dramatically less damage than intended towards specifically moose. When it hits a single lung at approximately 150 meters, it only causes a "Very Low" bleed rate, which results in a very lengthy, almost 1 km track.
In contrast, the caplock muzzleloader and its .50 cal minie balls, at the same distance, seem to consistently hit double lungs on moose, causing a "Medium" bleed rate and a much shorter track.
This seems like a bug, as the two ammunition types have similar stats, albeit slightly different. This problem also only seems to occur with moose, as I've tested against black bears and saltwater crocodiles, both of which went down with no problems from the sabot bullets. I also tested the .308 against moose, which resulted in a single lung hit with "Low" bleed rate, and a long (but not as lengthy) track. These results also directly contradict the flavor text of the .50 cal sabot ammunition, which says it is "perfect for hunting large deer such as elk or moose."
I'll continue to test this against other class 7-8 animals and post my results below.