Lets not forget brother R. Lee Ermey's sage advice:
"I don't want no teenage queen,
All I want is my M-14;
Ho Chi Minh is a son-of a-*****,
Got the blue b*lls, crabs, and the seven-year itch!

__________________
Half a league, onward...

I don't really think there would be time for any trade-ins if the SHTF. You could probably find something you like taking from the dead or wounded in the streets.

Has Sipowicz chimed in yet? I'm thinking his idea of survival would be stocking up on vodka and olives.

M110 Semi-Automatic Sniper Rifle

Why mess around with anything else? To the best of my knowledge this is the current top weapon used by our forces.

For an affordable SHTF rifle the sks is tough to beat. I just finished up checking over a Chinese norinco m14 but I haven't test fired it yet. The headspace is ok, I installed the national match OP rod spring guide with the HD OP rod spring.

if it hits the fan you should have those tools ready and lots of food to feed them

Heck; I got one in my LEG and hiked out 4-5 miles from where I slipped and fell on the bullet.

This said, whilst I like the 22lr, it's nowhere near the kind of stopping power to diffuse most any situation unless you are attacked by rabbits and squirrels.

If we are talking about a real down and dirty situation? I'm not going to be alone. I WILL have a co-pilot, and one of us is carrying a 308 AR. One of us is carrying a 556 AR. It's simply not a realistic thought to live in a city and have no one around you to help pick up some slack. I know where my friendly neighbors are. My sons live close by. The thought of bugging out is not real. The roads will be closed. Even if my co-pilot is a non shooter??? They will be carrying something.
Be sure whatever rifle you have for this situation is stone cold reliable, and not a picky eater. Nothing worse than having to go back to a burned down house to try and recoup a fist full of special loads Give me a hand full of whatever's clever chambered in what I have, and it will work.

Lewis Machine and Tool MWS, same as the British military is using these days as a DMR in the 'Stan. AR-type design in .308 goodness, excellent long range accuracy, devastating up close, 20 round capacity, rail space for accessories, short and handy, and very reliable. What's not to like?

I'll take an M-16 A2, or maybe a M203....

or my No.1 Mk III* SMLE in .303. Clean Break.

Not much to choose from for me. Our only rifle is the Garand in the safe that is nearly as old as I am. It shoots about 2 MOA when I do my part.

Admittedly, I like having experienced assistants when involved in anything important.

It has a scout scope mounted using a UltiMAK mount to make up for my aging eyes. Yes, I realize that is sacrilege to make a proven battle rifle wear one of those modern, tacticool optics. But, it really works well.