The mags we are all debating are exactly what you speak of... although not produced in Canada they are imported.
Alexander Arms made the .50 Beowulf mags from the ground up specifically for their .50 Beowulf upper.
The follower is different, the angle is different and the feed lips are different. They are specifically designed for the .50 Beowulf rifle alone. They are designed to feed .50 Beowulf ammunition and that calibre alone...
they are NOT .556 magazines in any way shape or form.
Therefore it is a .50 Beowulf magazine and our laws dictate it is to be limited to no more than 5 rounds of the .50 Beowulf cartridge.
The law is clear and has NOT changed.
The sheelple of Canada just believe anything their master's tell them, sadly that has not changed either. Pics below are magazines I have owned over the years since they were first approved for import by the RCMP, imported into Canada and sold in brick and mortar retail shops across Canada.