Put a Katana in my hand I'd likely be missing fingers within 10 minutes. I'm not good with sharp objects. Somehow, I always find a way to test them on myself.
Honestly, the best SHTF/Zombie Apocalypse rifle is the previously mentioned Ruger 10-22.
You could sling that rifle over your shoulder and forget it's there. Easy to aim and shoot. Reliable as anything. A brick of 500 rounds weigh a couple of pounds. Ruger has sold a bajillion of these things so they'd be easy to find in a closet somewhere.
Sure, they're lacking the "cool" factor that a proper "black rifle" has but they're practical. Rabbits and other small game would be made quick work of. Nobody is going to be shooting elk and moose in a SHTF situation.
Might not be the best man-stopper out there but a .22LR to the neck will really ruin your day.
Gophers around here used to be able to agree with your assessment of the 10/22.