Killing coup-plotters and their associates would happen immediately as soon as anyone began to execute a coup.

Lots of people have access to weapons (mostly for hunting, but still) and lots of people have done their mandatory military service and know that coups are illegal. They would certainly fight.

My point is that inviting that-- i.e. creating the situation where people have to fight and kill the coup plotters and anyone who sides with them, is a very extreme thing where killing only the plotters themselves is the mildest outcome.

This would happen as soon as a government said 'we're blocking the riksdag from meeting'. No one in Sweden from any political party in the Riksdag would ever do that though, it's of course unthinkable.