Wow. I just skim-read Volume 4 of the MCC report very quickly and have to say, it really makes some logical leaps.
The recommendations about "Reducing Gun Lethality" in Volume 4, Part D really do rely on generalizations from case studies in AUS, NZL, and the UK without addressing if violence shifted to other means. They acknowledge that the shooter received his firearms illegally, and plough ahead with the Canadian Coalition for Gun Control 's policy position on firearms in general without tempering things by admitting that those policy prescriptions would not have made a whole lot of difference. The recommendations also imply a requirement for a new non-restricted registry, as the whole "prohibiting ammunition purchases" thing absolutely requires that. I also have no idea how their idea to restrict ammunition quantities would work, but it would be very costly for little payoff.
There is some good stuff like educating on gun laws and hotlines to report suspected illegal fireamrs (which seem designed to undermine the CFO though), but then they drop the ball by generalizing about things that everyone already tries like "better coordination." That's kind of like saying "try harder" without offering any executable ideas. They're coming to a party without a casserole.
To be blunt, I didn't read the whole report and examine its logic. But the initial impression I get is that most of the firearms-related recommendations are fluffy pablum and the policy positions of "the usual suspects" that is of limited value, and indeed un-executable in real life.