This seems like a bit of an odd way to accomplish what they are trying to do. The law seems to target the export of these weapons to cartels rather than US individuals who simply do not use .50 cal weapons in crimes.

The added component which allows victims to sue manufacturers reminds me of the scene in Thank you for Smoking where they discuss suing general motors if one of their vehicles is used during a drunk driving accident. It’s pretty dumb and undermines the whole law.