... because SWCs just won't group. I figure I need 0.358" diameter at least because the groove diameter is 0.3575". The beginning of the throat is 0.3615" just ahead of the case mouth, so 0.360" probably would not be too large (?) and I can always size downwards.
If anyone has been down this road already with a 77/357, I'll be happy to try/start with whatever has worked well in yours. I'm planning on buying an NOE mold when I find a pattern/style that shoots well.
Thanks!
Edited to add: I've got 200 - 300 water dropped Lee C-158-SWCs that measure 0.3575" diameter if anyone should wish to trade; they won't work for me.