"I used 4831SC in .5 grain increments."

I assume you worked up in 0.5-grain increments?? From what starting load? How many batches at 0.5-grain increments did you fire? What happened? Did the groups tighten up as you increased the powder weight, or did they open up? Or stay the same? Regular H4831 has always given me pretty good accuracy in the 7mm Mag., but I've never tried the SC stuff.