The gun in your hand is the best gun to use for self-defense!
If the only gun I had left was a Ruger Blackhawk, I wouldn't feel particularly undergunned. Today my Sweetie and a bunch of friends spent all afternoon at the range shooting cowboy guns — rifles, revolvers and shotguns — shooting gobs of ammunition. I always carry when I'm out of the house, and I always have a hot weapon on my person (other than the target guns) when I'm out shooting in the woods.
For the heck of it, I carried my 1956 Ruger Flat-Top .357 in a Ted Blocker concealment holster (actually, a really cool old George Lawrence design I talked about in the podcast this week) under a vest. We had a minor incident, but the fact that I was carrying an SA didn't bother me in the least.
Michael B