The old suitcase can be used to make a well equipted bag one with wheels carry alot of gear packed neatly and with thought youcan have a bag common to be seen and be ready at all times. Small takedown rifle and ammo be easy to fit in a bag like this
And old suitcase are sturdy, a bit heavy but sturdy nonetheless. You can carry a great deal of load with them but is not something as handy as a pouch or backpack to bring with you 95% of times, therefore I would use only when I'm on the move towards a new settlement.
Tbis loaded and placed in car. Or somewhere handy just as a pack is would be a way to have more than one kit ready at a cost much more mangeable for people