To me a kit gun has always been a handgun that is essential or at least handy for the activity at hand. Like some of the other tools one would need in the same activity, knife, hatchet, pack, tackle etc. When I was trapping full time there were certain things that were with me every day and essential to the activity. The Single Six was among those things. Same with packing meat or hiking or any other outdoor activity. My "kit" are those things that I deem to be necessary to the activity and most times a handgun of one kind or another is part of that kit. A kit doesn't have to be something packed away. In my case I consider those things I carry on me as part of my kit. If that makes sense.
By that definition, when is a gun
not a "kit" gun? Why don't we have a "kit" knife or "kit" hatchet?
You may have guessed that
I have come to consider the whole concept rather inane. 
