As I recall, one "gauge" is equivalent to the diameter of a one lb. ball of lead, and the higher the "gauge", the lesser the amount of the lead, and accordingly the less the diameter of the ball of lead used to make the "gauge", and therefore the smaller the bore of the weapon. Which is why a 10-gauge shotgun is much more powerful than a 12-gauge, which is much more powerful than a 20-gauge, and so on. So, by that logic, a ".12" gauge shotgun would correspond to a much greater amount of lead in the imaginary ball of lead (8.5 times more massive weapon than even the already-huge hypothetical "one gauge" shotgun--8.5 x .12 = 1.0), and therefor a much larger weapon bore diameter. Vastly larger than exists in the non-military world. Accordingly, the idiot who wrote the article was even more uninformed about guns than it first appeared.
It seemed a lot more humorous before I had to explain it in such detail.....
I saw the humor in it.