It talks about a "well regulated militia", and that was because the US didn't have a standing military yet, so it depended on the people for defense.
Personally? I think that after we stood up our military, and made it one of the most formidable on the planet, that is when the 2nd became obsolete. And, while I'm from Montana and didn't know what store bought meat was most of my childhood, I'm also a hunter. And, if a person wants a 6 shooter, or any other kind of handgun, I would like the ammo to only be around 9 rounds before you have to reload. If you want to own a rifle, bolt action or lever action rifles are perfectly fine, and again, I'd like to see an ammo limit of about 10 rounds or less before reloading.
Semi automatic weapons that fire a round with each trigger squeeze that holds 30 plus rounds? Don't see the use of them. Handguns are better for home defense, and the AR-15 is designed to throw lots of ammo downrange quickly, which the only use I could see is in a war zone. And yeah, I served 20 years in the Navy.