Haven't hunted all North American big game with any single .30 caliber round, but have hunted big game with various rifles in .30-30, .300 Savage, .308 Winchester, .30-06, .300 WSM, .300 Winchester Magnum and .300 Weatherby. The winner is the B-29, a slightly "sub-.30" that has a magic none of those others possess. 7.5 - 55 Swiss?
"Political Correctness is a doctrine, fostered by a delusional, illogical minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end."
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