Thanks guys. I lost the symmetry on that one, but at that point I didn't care Should kill just as well.
Thanks for the tips on rock cooking. I would have spalled that stone out if I could have, but nothing I have would break them up. Certainly I need to learn some better technique. I only heated the rock at 250 for 8 hours, I didn't realize it needed more time than that. Some of the stuff that turned out to be georgetown was inside cobbles I hadn't tried spalling. That was a mistake as that stuff works pretty good raw and I overcooked it and ruined it. Other stuff came out wonderful, and some of it is still too hard to spall. I'll keep after it...but after deer season is over.
George