Making guns highly restricted/illegal doesn't make them hard to get. Did making meth completely illegal make it hard to get? To make this even remotely feasible imagine the New Orleans 2005 door to door SWAT raids coupled with the worst part of New York's stop and frisk.

In France, where guns are highly regulated, full automatic military AK's can be had for a few thousand dollars. A bargain by US standards.

https://www.washingtonpost.com/news/worldviews/wp/2015/01/09...