Over the holiday, I was able to do some bullet casting. Using a Lyman dbl. 358212 I hadn't used since the very early 80's., I was getting badly wrinkled bases..I knew mould was clean..at first I thought something was amiss with alloy..then I remembered how long since I had used it..looked close at top edge of blocks..sure enough..sharp edges..I have learned to stone a VERY slight bevel for air escape. Mould was hot..so being careful, I used a fine India stone & just broke both edges..very next casting..and all others had perfect bases.
Also, this was first time I had used a near mint integeral handled Ideal 36071..bullets hanging up on bottom band of one block..using a hard lead pencil, I ran it around groove..paying particular attention to edges..any burr..or whatever it was was gone..and bullets dropped of themselves or at most light tap on hinge pin.
I was using a fairly soft alloy..so was running hot..noticed whiskers forming on Ideal dbl. 358216...let up on contact of dipper spout to sprue c'sink, to allow alloy to run out up sides of spout..this cured problem. Sometimes you just gotta do things little tweaks on the fly.