[paxunix]

"Mass murder weapon" versus "justified homicide weapon" is just a situational distinction that does nothing to address the fact that the physical thing is identical and inextricably tied to horrible, irrevocable actions. Your gun doesn't become a "justified homicide weapon" until after the fact. Up until then, it's always just a weapon because you can't prevent or enforce its use for a particular, sanctioned purpose.

[maxerickson]

They don't have to be identical physical things. That's what they mean by design space. What features (that affect things like range and rate of fire and accuracy and so on) should be legal on civilian weapons?

For the US even something like limited internal magazines isn't politically tenable (a 5 shot internal magazine and manual action would still be useful for hunting but could not be used to shoot hundreds of rounds per minute into a crowd of people).

Hell, I won't be real shocked if nothing gets done about bump stocks (which don't really have any purpose beyond shooting for fun).