If I had the time, I’d use Pathfinder stats to run a full simulation. What I know is that in Pathfinder, a commoner has 3 HP and can thus survive 1 round (albeit staggered,) and a rifle wielded by a commoner has a 35% chance to kill ~95% of a cat on average (1d10 damage vs 3 HP.) Also cats have +14 Stealth and I assume they wouldn’t be charging through an open field, so a commoner has ~10% chance to notice one (nat 1 or nat 20 required.)