I never experienced hang fires with CFE223 but did experience big differences in apparent velocity which resulted in erratic groups no matter what 223 load I was shooting. This got worse as temperature dropped. I still have half a jug of it that will probably get dumped into my gallon Oil jug for disposal.I experienced delayed ignition and hang fires with CFE223 one morning in the mid 30s. Velocities were all over the place.
Gave my jug to a friend that loves it, not a powder for me.
JMHO