So you're not completely defenceless if your rifle fucks up?
Revolvers seem simpler to maintain
Revolvers are also more flexible with the ammo you can use because an automatic needs the gunpowder to fall within a certain range of energy to properly knock the slide back and eject the casing. Can the ammo fit into a revolver's cylinder? Then it's probably gonna work. Not so with automatics.
This may be important in any kind of scavenging or guerilla warfar situation.