If the rig is selected wisely, battery life is not really a problem anymore. I operated my handheld for weekends in contests with a single charge. A couple of AA Eneloops might give weeks of operation when you limit your on the air time (e. g. by scheduling contact times).
One thing that helps conserving batteries is a good antenna. It allows to cut down power on the transmission. I have a NR-770R on a Kenwood TH-F7E. That is a 3 feet antenna on a transmitter with the size of a pack of cigarettes.
For the purpose of the gun club CB might have been a better choice.