lee .452 6 cav is casting small

[rufracer]

First batch ww cast at .452-.453. This batch ww is .450-.4515 what gives? Need more tin, antimony?

[mroliver77]

What changed? Alloy? Temp of alloy? Temp of mold? I dont believe I have ever experienced that drastic of a change. J

[JohnH]

I would suspect the mold was being run a bit hot. Do the boolits have an obvious shrunken area in the middle of the boolit or a color change there? Only other thing I can think of is mold release. The spray on grafite stuff. This will make a mold cast boolits almost exactly different in diameter as you report. The stuff is great for getting an oversize mold down to size, lousy for a mold that throws true diameter.

The last Lee mold I had was eat up with machining fins at the parting line. It was 312-155. Cast .314, ideal for my purposes at the time. Cleaned up the fins and lost .002" diameter

[Leftoverdj]

I would suspect the mold was being run a bit hot. Do the boolits have an obvious shrunken area in the middle of the boolit or a color change there? Only other thing I can think of is mold release. The spray on grafite stuff. This will make a mold cast boolits almost exactly different in diameter as you report. The stuff is great for getting an oversize mold down to size, lousy for a mold that throws true diameter.

The last Lee mold I had was eat up with machining fins at the parting line. It was 312-155. Cast .314, ideal for my purposes at the time. Cleaned up the fins and lost .002" diameter

John knows.

[Calamity Jake]

First batch ww cast at .452-.453. This batch ww is .450-.4515 what gives? Need more tin, antimony?


NAH, your just squzzing the handles to tight. :kidding:

[rufracer]

i am running the mold a bit hotter, thats the only change other than adding some 50/50 solder.

[Leftoverdj]

i am running the mold a bit hotter, thats the only change other than adding some 50/50 solder.

That'll do it. Hotter alloy will shrink more as it loses heat. You could increase the antimony in your alloy to gain a little diameter.

[rufracer]

Ok ill try that.