I never shoot any bullet over 55 grains in any of my 223's......with one exception. I have some surplus 62 grain stuff that's intended for the when-the-crap-hits-the-fan scenario. I want as much speed as possible out of the 223, because that what works best for me. I limit 223's to coyote sized critters and smaller, and if I want to hunt deer, I use something bigger. Despite the claims one reads on here and other places, the 223 is not an ideal deer cartridge. Yes, people kill lots of deer with it every year, and I have in the past, but there are too many better choices out there for one to use. The 22LR has been used to kill everything from a grizzly bear to an elephant, but that certainly doesn't mean it's ideal for that kind of work.