What is the minimum rifle caliber requirement for big game hunting?

The minimum rifle caliber requirement for big game hunting is correctly represented by the specification involving a centerfire rifle with an 85 grain bullet that delivers at least 1,000 ft.-lbs of impact energy. This requirement ensures that the ammunition used is sufficiently powerful to ethically and effectively hunt big game animals, which typically require a greater stopping power to ensure a quick and humane kill.

Understanding the importance of impact energy is crucial for big game hunting. The minimum threshold of 1,000 ft.-lbs is established to ensure that the energy delivered at the point of impact is adequate for penetrating the animal's vital organs, leading to a high probability of a successful harvest while minimizing suffering. The bullet weight of 85 grains aligns with the necessary performance characteristics expected from suitable ammunitions for large animals.

In contrast, the specifications presented in the other options do not meet the established criteria for hunting big game in terms of caliber or energy. For instance, a shotgun at 12 gauge is not considered a rifle and thus does not qualify under the same category of restrictions. The muzzleloader mentioned (.50 cal only) also serves a different class of hunting and does not pertain to centerfire rifle requirements. Meanwhile, the centerfire rifle option that mentions a 100