Many with intent to kill will kill without a a gun. But many more will not. and of those who do, more victims will survive a stabbinf and there will be less innocent bystanders.
For example if Adam Lanza did not have access to a gun. would he have gone through the school stabbing? Maybe maybe not. If he had though what would the outcome be? On the same day as Sandy Hook, in china a mass stabbing took place.
Here are the results:
Sandy Hook: dead 28, injured 2
chenpeng: dead 0, injured 24