I've seen deer killed with a .22lr (by a poacher as it is not legal to do so here) but I sure wouldn't want to try it. I like the idea of a larger bullet, I'd take a handgun cartridge chambered in a rifle over a .223, but that is my opinion. I also had a friend that swore by his .22-250 for deer.

There must be a dozen threads on deer with a .223 in the last year...