Plenty of people 18-25 walking around Israel with fully automatic assault weapons. Plenty of mass murder there too, but rarely with firearms.
The problem isn’t the guns themselves. So debates about this gun or that gun, this law or that law, is pointless.
We might start with this country having a massive public health challenge in our failure to properly fund mental health counseling and incentivize its use.
We fail to concede the civil liberties considerations when one constitutional right (right against involuntary mental health detention) collides with a right that is natural and precedes the Constitution, (the right to possess weapons suitable to protect your home from incursion or invasion).
Until we concede that a lot more people need mental health treatment than either side is willing to fund, we get no place. But that doesn’t matter because neither side, nor the courts, are pretty eager to deal with the only solution - when people need to be locked up for their own protection (and ours) that needs to be done quickly without a lot of red tape while balancing the rights of the detained, especially after mental health stability has been documented by appropriate professionals.
Until then, America has enough guns that you could ban and confiscate 98% of them and it wouldn’t significantly reduce gun related crime, particularly random mass casualty events.
Meanwhile I’ll sit here and wonder why we have red flag laws where we confiscate guns from people determined to be too dangerous to possess them, but then we just turn them loose on the public at the conclusion of the hearing.