Fer what it' s worth, I agree with vapodog, the term is mostly used today by marketers just to make sales, basically it' s a fast for caliber round (in average loadings, not heavy loads), nowadays, that' s assuming something like 3000+fps for rifles, and 1200-1400+fps in pistol cart' s...but it' s mostly a marketing thing.

again, the " magnum" is an old winery term...nuff said on that though...why do they call them the V-8magnums? it' s big, and the name sells.