My brother has a Bausch & Lomb 6x Scopechief on his 222 Rem chambered Win 70A sporter. Works great for chucks. Nice thing about a 6x on a 222 Rem, is that you can spot your shot through the scope as the recoil and scope magnification match well. I have can 8x Leupold on my heavy barreled Sako 222 Rem, but I would be just fine with a 6x on it. A 223 chambered rifle shouldn't be much different.
If you are hunting faster moving targets up close, you may want lower power. Also depends on the weight of your rifle.
Overall, 6x is very useful.
