I strongly disagree with you on the topic of guns. Fully automatic guns are absurdly easy to manufacture, and mass shooters will easily buy them, or have them made, or will make them themselves. Now that technology of gun making is here, the only answer is that everyone is armed with high capacity magazine automatics. Smarter people will evacuate cities for a life in the country, the less smart or able will remain in said cities, having to live surrounded with guns. And let's face it, when everyone has a gun, people tend to be much nicer to each other. Finally, mass shootings are a function of how broken society is, and not of how many guns there are. Now check the following link to witness the simplicity of making fully automatic guns.
https://thehomegunsmith.com/pdf/Stengunplans.pdf
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