AR-15s

One other thing I just thought of.

We can debate on the use of 223-556 for defence in and around the home. That is not this post.

You can buy an "upper" for your new AR lower that is chambered in .410 shotgun.

Now you can unleash 20 rounds of buck shot with or with out a choke and your neighbors wont be dead.

If you plan on unleashing that 223 or 556 for defense in the city Id buy hollow point ammo just to limit penetration.