Thanks, guys, makes sense but the only thing I can't figure out why the deep grove? The 4 wings are only 1/10th inch wide and the band in front of the grove is just smaller than the wings. Maybe the band in front of the groove is land size and the wings groove size? I still need to get the cerrosafe from my brother to at least cast something so it is easier to measure. Sure is an odd looking bullet. This came in a lot of 10 English molds I just bought, the owner did not know what it was for either.
