I have run 4-5 runs with this new to me but pre-owned mould , it seems to be just plain fickle .
I washed it in Dawn , carb cleaner and finally brake clean . It continues to act like it has a dirty place uniquely placed on the Minnie style scrapper bands but only on one side . More tin helped but not for long . I ran the vent lines on both blocks and fussed with the sprue plate . I don't know how much difference that makes in a nose pour mould .
Being a ladle guy with a brand new RCBS ladle I resorted to pressure pouring . I still had an occasional fail to fill out but with whiskers . Very frustrating .
250 pours today with a full ladle that will carry a little over 1600 grains per dip pressure pouring the last 150 , it seems to be cleaning up . I can't figure what might have been gummed up in the bands .
This is the only mould I've used that needed to be pressure poured .
At this point pressure pouring seems to be a cure for the fill out but it would be nice to know why .
I've poured it with 50/50 WW-1/20 , 1-40 and straight lead . With 1/25 to 50% rejects . Yes the pin is hot . No there isn't any oil or sprue/pin lube in it .