It was a Studebaker tracked creation, light[carried in planes] and carried cargo. As for the mission; the Aleution highway??
Well, on to another question I suppose: The answer is: The Weasel (M-29) was concocted by General Marshall after a meeting with Lord Mountbatten who introduced Marshall to one Geoffrey Pike an "eccentric" (as if there were any other kind!) British scientist who had devised a plan to divert large numbers of German troops from Western Europe and the East by using commandos with special vehicles to allow them to raid in winter and in poor / swampy terrain. Facinated by Pike's ideas, Marshall went to the Studebaker automotive company and gave them a contract to design what became the Weasel to fufill this requirement for a specialized commando raiding vehicle capable of traversing deep snow, swamps and, other generally impassable terrain. This was also the orgin of the US / Canadian 1st Special Service Force.
Yes, Norway was mentioned along with Ploesti in Romania (!) among other possible targets for commando raids.....
Well, the Germans and US had a 75mm cannister round too. But, these are far smaller than historical ones used in the 19th century that went in smoothbore as large as 11 or 13" in the case of naval guns of the period. As for small arms, the largest manufactured shotguns were 6 gage or 1 bore (that is, 1" in bore). These were often used for big game hunting like the famous Holland Nitro Express guns.
ok, the answer is 18.1-inch bore. the san shiki anti-aircraft cannister shell for the yamato's main guns (designated #6 shot if it remember.) the shot load varied, from several hundred 1-inch diameter steel balls to steel balls with a 50-gram explosive charge (about the strength of a 20mm cannon shell.) wasn't very effective though.
The 3 Shikishan Shell is not a "shotgun shell." Its closest equivalent was a case or shrapnel round. It did not come apart at the muzzle of the gun. Instead, it was fired to altitude using a time fuze that initiated a burster charge and then scattered the individual incendiaries ahead of it just like other case rounds did. It did not have a filler of "steel balls with a 50 gram explosive charge." Here's a thread explaining the round in detail: http://www.ww2f.com/information-requests/15074-sanshiki-shells.html
