The choice of caliber for your hog hunting rifle depends on various factors, including your shooting preferences and the size of the hogs you're targeting. Popular calibers for hog hunting include .223 Remington, .243 Winchester, .308 Winchester, and .30-06 Springfield. These calibers offer a good balance of power and accuracy for taking down hogs at different ranges. Ultimately, the best caliber for you will depend on your shooting skills and comfort with the firearm.