To me, this dictates always carrying which excludes the bigger guns.
You hear this a lot, and it makes my head hurt every time.
It seems to me, you are carrying that gun on the off chance you need to shoot it, and in that case it better do the job.
So the first step shouldn't be to pick something you like to carry. You need to pick something that you shoot really well, because I'm assuming when the SHTF, you are going to need all the help you can get, and you need to pick something that provides some reasonable margin of error in the oomph department.
Then you figure out how to carry it.
