Hog rifle is a southern mountain term [includes Ozarks] along with squirrel rifle, bear rifle, even "human rifle" [used in Mo-Ark area] and other similar terms. I have seen the term "pea-rifle" used too. Randolph, the chronicler of Ozark language, lists a bunch of such terms. They relate generally to a rifle's main useage, which is in turn often related to caliber [e.g., bear rifle vs squirrel rifle]. Hog rifle, though, I think relates more to the late period when big game declined and a man's meat came from killing his hogs--often turned out "wild" to fend for themselves, but sometimes slaughtered in a pen. A hog rifle would have been whatever caliber you still owned...
