COWW boolits pop right out of the mold but strange hard alloy ones dont

[bigjake]

First off... Happy New Year!

Anyway, I have been casting nice bullets in the lee .40 cal 175 gr.TL mold with clip on WW

When I use this hard babbit type alloy, it casts light bullets about 160-165 gr. and stick in the mold terribly. I have to beat the center bolt to death to release it.

Do these type alloys expand more than WW's?

[Cherokee]

IIRC, the more the lead content, the more contraction. When you say babbit type alloy, this means high tin /antimony content and should be cut with pure lead for a more suitable shooting bullet. The weight you mention in relation to Lee's stated weight would support this being much harder than you need.

[Tom W.]

If it's nickel Babbitt it's 90% or more tin. Makes for one mighty hard boolit, but as you found out, they are also light...

[JSnover]

You can add a little to your other lead if you need to but there is no need to cast boolits of straight babbitt. If WW is casting well, save your babbitt for mixing other alloys.

[rintinglen]

Depending upon the specific babbitt metal you have, you might be better advised to solder with it than cast boolits. Even lead based babbitts typically have less than 66% lead. Most babbitt metal these days is 86-90 % tin, 8-12% antimony, with copper, arsenic, and trace amounts of lead, iron and aluminum making up the balance.
Stop wasting your precious tin and mix it 1-40 with your scrap lead, range metal, or COWW, for great casting alloy.