I'm with Fiver on the nice weld bead.... next part I have reservations about even discussing so will preface saying you didn't hear it from me.... think in the abstract,to whack or not whack(sprue plate abuse?); Recent changes in the ole casting setup,got RUNNOFT out of the best durn setup,ever. Saw a change from a std propane torch head,which was there to coax a little more performance out of recalcitrant moulds....to a Coleman single burner,available at Walmert,camp burner. Here's the possible abuse. Once your mould is up to temp but the bullet's base "needs" some experimental help,flip it sprue plate down over the single burner.Huge difference in the heat transfer between the small semi focused heat of the torch head and the way the single burner's act. Like a tig torch vs OA torch,both using the same rod. Watch what happens to not only the base,but you should see,by continued abuse.....it starts to "run" up into the bullets body.
Sorry for the run on paragraph,haven't had any coffee yet.... pots over there gurgling.