Shrinkage?

[Pitchnit]

When casting 45 acp with a Lee 6 banger is there a difference in shrinkage between, say, wheel weights and 8/1 range lead and monotype. I'm getting .451 with the range lead and mono and was getting .452-.453 with WW. I was casting at 725-750 per my thermometer but some were pretty grainy. Seemed like it ran best at about 3 cycles per minute. What should I be thinking about before I open up the cavities .001-.0015. I ran about 600 of these. I can load a few, maybe a 100, and see how they shoot. Ive only been at this for about 1 year. Regards-Pitchnit

[runfiverun]

tin and antimony make bigger boolits.
the more of those you have in your alloy the bigger the boolits will be.

mold temp can have an affect on your boolit diameter also.
i recall some nei molds that walt would put the optimum temp of the mold on the box and warn of anything hotter pouring a smaller boolit.

using visual clues of the boolits coming from the mold will help you keep them in the same temp range.
there is nothing wrong with cooling a mold off during casting.

[mdi]

Not completely sure about how much difference alloy will play in final size, but in the 3rd Edition of Lyman's Cast Bullet there is a chart that will tell you how much shrinkage occurs with alloys. I do know that casting temperature affects final bullet size. I was getting small bullets in a 6-banger 9mm mold so I dropped the temp. to mebbe 100 degrees above liquification and the bullets "grew" .001" to .0015". Same effect but a bit more dramatic with larger caliber bullets (I cast a lot of 250-265 gr. .44 cal bullets) but I don't have the measurements handy...

[prs]

If you get good results with WW, I see no reason to enlarge the cavities. I would enrichen the range lead/mono mix a bit to momick the WW alloy. The more lead, the smaller the cast in general.

prs