I think you will find that anything over 55 grains in the 223 will not shoot very good. Thats what most of us have found out. The Handi 223 has a 1/12 twist barrel which should, I say should, stabilize up to about 63 grains, but we have not found that to be true. If you are not going to handload, just get the WW Econopak of 40, get the 45 grain JHP loads, not the 55 grain loads. It is about $11.50 to $12.50 at most discount stores.