I wouldn't buy an AR anytime soon. They are way too expensive right now and impossible to get some parts.

This tree has too many branches. Rifle? Shotgun? Semi-Auto? Revolver? You gotta narrow it down. Plus, as you say, you've already got a couple home defense weapons and now say you just want a toy.

Well, if it's a toy, then just think of what you want to do with it. Then decide for yourself.

If it's truely for home defense, then I almost always say revolver in the handgun catagorie.

Shotguns are excellent for this, and I disagree with just changing the barrel. It would be cheaper, but it sounds like the one you have is more of a hunting setup. Would be better to keep it that way. Get a 500, add a pistol grip stock, ghost ring sights, and presto, the perfect home defense weapon (oh, and get rid of the strap Mossberg insists on putting on all their guns now. Retarded).

For rifle, I'd go lever action. Way more reliable than any AR or Mini14. Highly accurate at short ranges. And you can get it in a variety of calibers. You can get one in .357, then buy a .357 revolver. Now you have the perfect home defense combo. One type of ammo. Best of both worlds.

And you aint never gonna need a 30 round magazine. If you do, you're in way over your head and you should be considering escape routes at that point, not killing bad guys.