Lead alloy problem, Need help/advise please

[Wildcat66]

I have been using wheel weights for my handgun casting for years without a problem.

Recently a friend who works for National Tire and Battery gave me some lead bars that he said
were from reclaimed batteries.

My 20# Lee Furnace was about half full when I topped it off with the lead bars.

Now the problem.

My boolits are casting undersize. Using a Lee .356 mold for my 9mm pistol, they are coming out from
.345 to .355.

Is it possible to empty the furnace into ingots and then refill the furnace with pure wheel weights and gradually
introduce the ingots to the mix? Say, 20 to 1 ratio?

Appreciate any help you guys can provide.

Nick
West Virginia

[jsizemore]

I'm assuming your NTB bars are pure Pb. The casting temp of pure is higher then COWW's. You can either up your casting temp or add tin to help with fill out or do as you suggest and add smaller amounts of the NTB bars. My pistol casting alloy is 50% COWW/50% Pb with 2% tin added cast at 650-675F. If your alloying tests aren't right you can always remelt. Good Luck

[Springfield]

If your bullets are coming out with 10 thou differences it isn't the alloy.

[Dusty Bannister]

If your bullets are coming out with 10 thou differences it isn't the alloy.

If you go back and look in the Lyman Cast Bullet Handbook, 3rd edition, they list a lot of contaminates that come from battery lead. Interesting you say that it is not the alloy.