Finally found a Lyman 314299 to ust for my 303 Lee- Enfield. Much to my dismay, it casts around .311-312. I'm casting W-W, with about 1 pound of magnum shot to 10# of W-W, also with about 1/2# of 60/40 solder. According to my Lyman thermometer, I've tried casting at various temps between 650-850f. I've also tried straight W-W, with the same results. I tried air cooled and water dropped, no measurable difference there either.
Tried ladle and bottom pour also, nothing has produced any repeatable, measurable difference. I have even checked calibration of my micrometers and dial calipers! Seems like I usually have this problem with Lee molds, but this is a first with a Lyman.
I'm kind of starting to think Lyman may have just given me an undersized mold, which in normal times would just be an aggravation, but with things the way they are, I have a feeling getting this replaced could be a real headache.
Can anyone suggest any other factors which may affect as cast diameter?
Andy