I have a Mossberg 500 20gauge on order and should be in by the end of the week. I read in one of the recent magazines that a 20gauge is plenty for HD. In order for both of us to be prepared, I may eventually get something for me.
The wife and I both have semi-automatics in the 9mm caliber...also a .22lr semi-automatic and revolver. All pistols interchangeable between us.
Then I have a carbine in the 9mm caliber and my Nylon 66 .22lr. Either rifle could be used by either of us.
I've tried to stay with 9mm and .22lr for the "emergency" preparedness/bug out weapons. JMO