Think about it this way...in SHTF, folks get the ammo they need, how much .22lr will really be available??
It'll get wiped off the counters the first day...whereas .22WMR will likely take a few more days to run out...
remember last summer when it was hard as heck to find .22lr at all??
My local Walmart carries four brands of .22WMR, the local sporting goods stores a few others, and LGS's always have a few boxes...
trick is to stock up beforehand...certain times of year are key, because of typical weather emergencies happening...
so take advantage of online ammo sales to Brick Up
And have More Than One Option...you'll need a .22lr, a .22WMR, a 9mm of some type, a .40 Glock cause cops carry lots of that,
2.23/5.56, .30-30, .30-06, .308, .45ACP (glock or 1911), .45-70 are the startups...with all those popular caliber options,
you'll have a wide array to choose from to use, and when one runs out of ammo, you grab another & keep going...
Military currently uses the M-9A1 berretta (9mm), M-4 (5.56), and M240B (7.62/.308)...which means after-battlefield opportunity...
cops use a wide variety of calibers, but mostly 9mm, .40, with a few using .357SIG, and .45ACP...
most cop rifles are either AR-types in 5.56/.223 or snipers in .7.62/.308, so that gives you compatibility with military ammo.
Not to mention the 12-gauge shotguns both use...but in TETOWAKI, mil-spec/cop ammo will be almost impossible to buy.
far easier to remove from DB's post-battle.
Just for fun, say we have a massive zombie (weaponized rabies) outbreak...you take your initial ammo supply,
and supplement it with that found on DB's spread all over the landscape...check the ammo pouches for extra mags...
weapons won't be hard to find...as the zombies just want meat...so there will be easy guns,
but likely emptied just before the owner was eaten...still worth checking the chamber/mag...every bullet counts...
and that's a TETOWAKI...total breakdown of society/world...
watch any zombie movie or end-of-the-world movie for more options...like "The Road" or "Mad Max"
SHTF usually means a Temporary, but possibly 2-weeks long to a year of issues...
which means eventually things will return more or less to normal, meanwhile, you're on your own.
In that case, you hold your position and bunker up, or didi mau to your bug-out location...
Hurricane-type situations, major flooding, tornado outbreaks, Watts Riots, that sorta thing...
Since Law & Order are expected to be re-instituted, you try to keep out of trouble, but defend you & yours...
If you've got a decent amount of ammo stored up in a safe/fire-locker, & plenty of food/water, you're fine.
Don't go hunting for trouble, it'll probably find you instead.
If you live in a wood-frame house, find at least a concrete block/brick home ASAP...preferrably something stronger...
If you live on a flood plain, move to Higher Ground...or build up your property to be 3' higher than the 100-yr flood mark...
Tactical Home Prep tends to be far more important than what you put in it...
Burglar bars are a requirement if you have low windows...stop zombies and gangs...
basically, if you are prepared for hurricanes, major flooding, zombies & New Orleans Residents, you have all the bases covered.