I've started some very preliminary work with CFE 223 in the 204. I'm shooting a Savage model 16 1x12 twist with 22" barrel. I'm not at all pleased with the accuracy using 32 zmax or 39 sbk's. I mean they shoot okay, but haven't found a combination yet that gives me the kind of results I've come to expect out of this 204.
The 32 zmax's average group .810, and the 39 sbk's .624. I did manage one group of .289 and 2 more of .468 and .405, but just haven't really been able to get them to settle in and be consistent. 30g gives me about 3,920 with the 32's and Rem brass. 30.9g (book max)gives just over 4,000 fps.
With the 39's using 28.7g I'm getting about 3,675 fps and 29 gives about 3,765 fps. The ES and SD's aren't all that good either.
Also proving to be mediocre in .223, but so far outstanding in 22/250 with 50vmax shooting in the .3's at ave of 3,885 with just 37g.
Sorry to be so long on the post.