Granted, they are mostly buying the AR pistols.
The ATF is only trying to ban "shoulderable" ARs, though, so urbanites will still be able to kill each other with AR pistols.
Meanwhile, the ATF wants to round up suburbanites who actually care about having an arrest on their record...thus the administrative shoulderable ban (with no new law being passed by Congress).
For the Left, some deaths are worth stopping, and others are not.