It's getting pretty scary out there. People are making a run on the gun dealers, snatching up anything black they can (saw the lack of black rifles first hand at 2 shops yesterday, everything was gone). While myself and Ash are already well prepared in the black gun department, neither of us are terribly well stocked in ammo due to a recent shooting trip which involved both an M16 and an AR-15 with a Slide-Fire stock.
Ammo isn't in shortage due to the recent election, like it was back when Obama first got elected into office. It's gone because people are stocking up on guns AND ammo in fear of bans. I don't think they fear ammo being banned, they fear being able to buy it in bulk. Ammo in .223 was 100% gone at a shop I was at yesterday (one guy there got the last 500 pack of wolf, all the brass cased was long gone). This is why alternate calibers need to be considered.
I've been given a hard time for too long about this. I love slightly odd calibers. One of my favorite rifles is a Winchester Model 70 (superior to a Remington 700 imho) chambered in .300 WSM. The ammo is expensive and hard to find. As a result, I hand load, which draws constant harassment. I have quite a bit of this ammo on hand due hand loading.
As for smaller, shoot-them-in-the-head calibers, .22lr is not the most viable choice. Low cost .22lr ammo is near-impossible to find. While I have a ton of it, I've also procured a .17hmr. The ammo is significantly more expensive but still plentiful, something that was also easy to find during the last run on guns and ammo.
Getting to the point, stock up when you find ammo. If you don't have a black rifle, don't sweat it, get something else. Learn how to shoot quickly with a bolt rifle. Calibers such as .270 are very easy to find good ammo for and have taken many many many deer. They'll be fine for defense, at longer ranges too.