undersized Lee mold

[blackhawk4545]

My new Lee .50 cal , .490" round ball mold is dropping balls at .483. Thought about "Lee-menting" them, but .007" is an awful lot to expect. What should I do? Send it back?

[JonB_in_Glencoe]

If it's .483 and near perfectly round, I don't think you'll be able to Lap a round ball mold equally larger in all dimensions. BUT, if it measures near .490 from sprue to opposite the sprue and .483 on the "equator", so to speak, then maybe Lapping larger is possible ...It'd takes steps with progressively larger balls ie: Lap, cast a new ball, Lap, Make a new Ball...repeat.

Personally, I'd send it back to Lee...After I double checked and triple checked that the mold is actually casting that small. Have you calibrated your Mic lately ?
Jon

[Dusty Bannister]

Thicker patch?

[blackhawk4545]

JonB - Mic is calibrated. Ball measures .489 at parting line, .483 the other way.

Dusty - A possibility, but wanting a 180 gr ball. Right now only 170 gr. Another .007" would get me pretty close.

Would my pure lead shrink that much?

[JonB_in_Glencoe]

OK, My first suggestion is to send it back.

But, if you want to try and lap it out, I think it may work, unless I'm overlooking something? If I were to Lap it out, I'd get some .490 round balls that measure .490

[Dusty Bannister]

If you are at 170 grains, you are pretty close to correct. 180 grains will not be a correct diameter, but slightly oversized.
See this link.

http://www.beartoothbullets.com/rescources/calculators/php/roundball.htm?v1=.490&v2=2876.1

If you insist on lapping larger, just to get the weight you desire, keep in mind that the size of the grit will need to be added to the diameter of the ball. And this will actually be two times the grit size. I would suspect that you will find a consistant weight more important than the actual weight of the ball. It will be your choice and you probably should consider wether your lead is pure or with tin and other metals present.

[blackhawk4545]

Dusty, thanks for the link. Yeh, I' m not quite as concerned about the weight as I am about the out-of roundness. .483 - .489 on the same ball is just too much. I just received Dutch Schoultz's book and want to get this right.

[JonB_in_Glencoe]

another thought, Have you tried casting with the Lead at hotter temps...then try lower temps...to see if that changes anything?
Doesn't the sprue puddle freeze instantly or does it take 5 to 6 seconds to freeze ?
Jon

[blackhawk4545]

It takes about 5 or 6 seconds. A few wrinkles until it gets that hot, then things smooth out.

[melloairman]

JonB - Mic is calibrated. Ball measures .489 at parting line, .483 the other way.

Dusty - A possibility, but wanting a 180 gr ball. Right now only 170 gr. Another .007" would get me pretty close.

Would my pure lead shrink that much?
I peened a couple of molds last week and pulled a couple thousands with out flashings . You can file to get the fit you want or file and remove the raised portion all together . Marvin
http://i301.photobucket.com/albums/nn55/melloroadman/IMG_7542-Copy_zps6ba8c92e.jpg (http://s301.photobucket.com/user/melloroadman/media/IMG_7542-Copy_zps6ba8c92e.jpg.html)