How would that work, exactly?
“They talk about “replacing” large caliber weapons with small ones via legislation. How would that work, exactly?”
What legislation? President Ocasio-Cortez would simply sign an EO ordering all weapons larger than .22 cal to be turned in within thirty days or owners would face arrest. Secretary of the Interior David Hogg would order the formation of a Civilian Confiscation Corps (CCC) made up of high school age youth to go door to door seizing those weapons not voluntarily turned in.
Tent city prisons to be set up for the recalcitrant.
Simple, huh?
;^)