colorado clyde gives some sage advice, as usual.
I don’t have the vast experience of most on this forum, but I have spent some time trying to decide whether the possibles bag-shooting bag-haversack nomenclature was just semantics or if there were real differences.
According to The Complete Blackpowder Handbook by Fadal, somewhat paraphrased:
The old time kit included a hunting bag, also called a shooting pouch, erroneously referred to today as a possibles bag. The shooting bag was a repository for vital shooting necessities, such as spare lead balls, extra flints for the flintlock, nipple wrench for a percussion rifle, small screwdrivers, and other devices.
Along with the shooting bag or pouch some historians claim there was a possibles bag. In theory, the name alludes to the possibility of finding almost anything in it. The possibles bag was probably a larger pouch in which could be found a bit of tobacco, spare gunpowder, flints, patching material, fire-steel, etc. In short, the possible bag was a catchall. Some students of the Far West don’t buy into the possibles bag story. They think possibles simply meant an array of gear, regardless of how or where it was carried.
Some people are adamant about the difference:
“The shooting bag is not a possibles bag. It should only contain those items necessary to operate the gun. The goal is to have your accouterments organized and handy enough that you won’t be fumbling around on the shooting line. When you have it all organized just right you should be able to load your gun with your eyes closed or in the dark of night if necessary.”
“Other items that may be needed for a day hunt such as; lunch, a container of water, compass, fire starting materials, etc. are carried in a separate possible bag or haversack.”
Others think that it is your bag and you can put in what you want and call it anything you wish.
Either way, there is a tendency to fill any bag or pouch to excess, particularly when you are new to the activity.
Most important: have fun!
Ron