Well, it's not doing a very good job of that function, is it? If countries without a second amendment are having less children shot in schools, then it's literally doing the opposite of protecting life.
I've actually bought several guns in my lifetime. Including - completely legally - in countries that don't have a Second Amendment equivalent, and don't have school shootings because they only sell guns to people who are INCREDIBLY safe, and even then only if there's a very good reason for the gun. So, apparently, the Second Amendment has nothing to do with my own ability to have a gun, it's to do with the ability for sketchy weirdos to have a gun.
But if you're just to tell me what I've heard and when, then clearly my own experiences should be ignored because you know me better than I do, apparently.