"The Real Deal"
Not really alot of differences, the .223 rem round is known to be more accurate in rhe 223 rem, and 223 wylde rifles. The chamber is tighter. The wylde allows the use of either .223 rem or 5.56 also. The nato 5.56 chamber is fairly accurate too. However a handload .223 tuned to the rifle is by far the most accurate, seeings how you control the quality, and all will be exactly the same. Factory ammo is made with a high and low spec and as long as it falls into that production range its sold, if its outta the production range its not, so you get variances in bullet seating depth, and case over all length. They are all safe to shoot, it just can effect the accuracy due to variances. But never shoot 5.56 nato in a rifle chambered in .223 remington only since it will create an over pressure situation due to the cut of the chamber and cartridge dimensions at the neck.I've noticed that .223 seems much more readily available than 5.56 NATO at the brick & mortar shop where I've been buying ammo.
Ruger's page for my rifle model says that either will work, but I'm wondering how much difference there is, and are there any caveats I should be aware of?
I stay away from steel case for my ar's, I found the tula .223 does not have enough powder charge to completely eject and strip another round from the magazine, making the ar a bolt gun basically. I tried it in several of my ar's with the same results, did not function in my standard mini 14 either.