lamb, I have had the problem with cut on contact heads that are pre-installed with the small adapter. I am curious (maybe a little clueless), but are you using the heads on aluminum? I usually won't buy the cut on contacts anymore with the pre-installed adapter. I always use the long adapter (I believe 42 grains) and install the head to the adapter myself. I have not had any problems since then. But while installing them, I always spin test them just to be sure.