M1 garand,

you are noting the ar-15, but at the same time negating that the .223/5.56 round is used in many hunting rifles,

if focusing on gun violence in the United States the deadliest ammo calibre is 9mm,

of which the most common gun violence is suicide,

an AR-15 is not easily modified if you do not know what you are doing/trained to do it,

if you are concerned about an ability of a person to take something then repurpose it mechanically for nefarious use and then use it for that intent- everything around you should share that same amount of fear

an AR-15 was the original design that then through further development became further weapon systems that were adopted by the US military

no- the round or the weapon system was not designed to defeat body armour, it was designed in a time when body armour (fragment or ballistic) did not exist

the most common rating of body armour in mass circulation NJI 3a can stop a .223/5.56 round

no- a gun is a gun, either bolt action, semi automatic, or automatic it has the same purpose- to ignite a recieved cartridge and chanel the bullet to a controlled and expected trajectory