Wikipedia gives me the Kongsberg Attack, which was only 5 people killed + 3 injured. This is much much smaller than the 18 people killed in this elementary school, + the grandmother of the suspect (who was probably shot before the whole event started).
https://en.wikipedia.org/wiki/2017_Las_Vegas_shooting
Las Vegas shooting was 50+ people killed.
Orlando Nightclub: https://en.wikipedia.org/wiki/Orlando_nightclub_shooting
49 people killed.
It seems like dropping down to knife/sword fights would cut deaths significantly, unless you can show me some mass-stabbing numbers close to these 50-ish sized crowds.