The proverbial "Half-inch howitzer." :D
I don't want to claim originality on that phraseology:
There was a letter in the American Rifleman a month or so ago (I can dig up issue and page if someone begs me) about a team of quad fifties who used to pepper a North Korean road crossing from, oh, say, two miles away. They called their unit "Home Of The Half Inch Howitzer."
I hope the Canadians are smarter than we are and keep the sniper's name secret instead of making a big hoo-ha over him personally. There may be certain very barbaric rules of vengeance in play otherwise.
Terry, 230RN