For goodness sakes, I have been hunting for over 35 years and have been in dozens of different camps and clubs in more that 10 states. I have never heard the term camp gun being used to refer to a gun for self defense, or defense of the camp, or defense against animals or people. I have also never heard of pistols or revolvers being referred to as camp guns. Geez, do you guys really go to deer camp and wear big revolvers on your belts all day, like you are in the old west? Not in my camps. Perhaps the only reason for this would be if you are in Alaska or British Columbia.
A camp gun is a spare, medium caliber rifle with open sights, or a shotgun, with a medium to short barrel, that is generally worn but in good operating condition, that you have at camp to loan to someone in case their gun goes down, or for a visitor, or for quick and handy use in case you spot some game close by camp, or in case a friend comes in and says he has wounded a deer and needs your help to track it. Implicit in the concept is that the gun can't be one that is very valuable, since it might get stolen from camp, or damaged by someone you loan it to.
Big Paulie