What is the legal maximum capacity of shotgun in Canada?

It could very from state to state but I suspect the federal gov't regulates all that. In Michigan, the legal maximum capacity is 6 shells.

Improving answer: Canada is not Michigan. But within Canada, there are Provinces. So I think they can have their own gun and ammo laws that may be tighter than the National law. Also, there is often a difference in what is allowed for hunting and what is allowed for other purposes. For example, under U.S. federal law (actually a treaty) a shotgun used to hunt migrating waterfowl (ducks, geese) can only hold 3 rounds maximum. 2 in the magazine and one directly in the chamber. But for deer hunting with slugs, 5 rounds is OK in most states.