There are draconian gun laws in Mexico - however there are an over abundance of quality military grade weapons in circulation. The Mexicans weren't all that interested in US firearms because they're semi-auto and cartels (like Jihadis) prefer to "spray and pray".
USGOV worked hard to make the case for US firearms being sold to the cartels in Mexico but the best numbers that they could come up with was 6%. Hardly convincing. Thence came Operation Fast and Furious - 'walking guns across the US/Mexico Border' so that MEXGOV could seize them and blame the US -- but BATF screwed it up.
If the USGOV confiscates registered firearms in the US, you'll see Americans buying in Mexico (in a way Fast and Furious reversed). The weapons are military grade and you can get some interesting stuff down there including Barrett 50's and Dragonov Sniper Rifles.
The problem (an inconvenient truth) that USGOV struggles with is that the states with open carry laws have much lower crime rates than the blue-state urban hells with tight firearms control.
This is how the country voted in the last election. The red counties voted for Romney and the blue counties voted for Obama. The red counties have a LOT of firearms in private hands and the blue counties have less.
Call this your NATIONAL FIREARMS CONFISCATION MAP. The "blue people" have a lot of work ahead for themselves when it comes to disarming the rest of the nation.
OH CANADA
Canada is a big country with a total population that is homogeneous (for the most part) and is a bit less than half the total population of the State of California. I worked on a joint Asian Organized Crime Task Force in Vancouver and Toronto, helping from the American side (1999-2004) and let me assure you, the bad guys were very well armed.
Additionally, the Sinaloa Federation Drug Cartel is moving big time into Canada and establishing meth labs there on a large scale. They are armed too. If you don't believe me or think that I'm a crackpot, ask anyone on this forum who actually knows me. I've been around since they started making FJ's and a lot of folks out there know me personally. Canada's old problems with the Hells Angels, etc. will look like a pleasant memory. Just saying... Your disarmed populace it the perfect home for international criminals. It used to be only in the large urban centers, but that is changing. Good luck.