If there could be only one.

[BoilerUp]

12 gauge. Shots over 100 yards in a "defensive scenario" just are not realistic. Under 50 yards and up against multiple targets it's hard to beat a shotgun. And ammo is more than plentiful.

The only time I'd grab a shotgun over an AR carbine is if I had to blow hinges off doors, and that just isn't a defensive scenario. I'm just not a scatter gun guy, but I think part of the reason why is that I have 3 other souls in my house including two little ones, so precise shot placement and treating every projectile as a liability weighs heavily on me. Shotguns send a lot of liabilities downrange at once with a pretty large cone of error.

That said, it's probably the last thing I'd want to be shot by, so there is something to be said for their effectiveness.

[BoilerUp]

Sorry Jerry, but 6.8 as a go to is a pretty much a joke. Great round, but after you burn up your 3 mags of it, the gun is useless.

Why do you say that?

[velocity2006]

Why do you say that?

Likely implying that, in the situation we are discussing, specialized calibers will be much harder to come by compared to some of the more standard NATO calibers. After you burn through your stash of ammo it will be much more difficult to re-up on ammo compared to say 5.56.

[Uffdaphil]

Come to think of it, I would not be limited to one long gun. My scared sister and hubby a few blocks away who declared their house a gun free zone would be available as bearers and to load mags. I'd make them call me bwanna too.