Me personally S&W 627 8 shot Revolver .357magnum because revolvers don't jam. They don't have feed ramps,mag springs therefore no failures to feed or eject. The only real thing you have to worry about with a revolver is a ''DUD ROUND''. But the odds of you encountering a DUD ROUND are like 1 in a billion ( I am just going off statistics i read about dud rounds ). You can keep a Revolver loaded forever besides a 8 shots of .357magnum that is plenty and then i got some speed loaders ready. I also got a Glock 20 10mm so this would be plenty of ULTIMATE RELIABLE STRONG CALIBER ACTION. For a Zombie apocalypse,Armed Assailants doped up on PCP with the worst intentions for you and your family or whatever the SCENARIO is. What is your go to gun? you got to factor in ammo capacity,Big or small Caliber and Reliability.