My 223 never shot the cheap stuff good. Didn't even like the better stuff in the lighter pills. 69's shot best..Australian Outback and Black Hills. I even gave up on the lighter stuff, but after much more development when I started loading, found some workable loads with 55 SGK's. I am thinking it is not the rifle, but rather you just haven't found what it likes best. Yours may like a big jump or maybe close to the lands. It is difficult to determine this with factory ammo.