Funny, I instantly clicked on this thread when I saw the comination of the words "14 inch", "223", and "IMR-4227" all in the same line. I thought, "hey, what have I been missing?" I guess nothing, everyone else seems to be confirming what I know....no .223 loads using IMR-4227.
Just for kicks, I just took out my "Complete Reloading Manual for the T/C" and looked up all the loads under .223. None show IMR or H 4227 for Hornaday, Nosler, Sierra, or Speer bullets. The only place IMR-4227 shows up is under the Lyman bullets listing for cast bullets. However, it is not shown for RCBS cast bullets.
Sorry Rickt, unless you're using cast bullets, you'd better check your loads!