I’ve running CFE223 in my Anschutz 1771 .223Rem w/fast twist barrel. My load is under Berger 77gr OTM hybrids and 80gr VLD’s. Accuracy holds at around 0.5MOA out a fair distance {in good conditions).
I never put too much credence on the clean burning and reduced copper fouling aspect of the powder. However, CFE powder availability has generally been excellent over the last few years, so I’m a convert from some older powders.