Got some auto body alloy

[waynzwld]

I had a plumber friend give me about 10lbs of auto body alloy :-D, says "30% tin" on the foot long sticks, along with 1 stick of "tinners solder, about 3/4" wide, 1/4" thick and also a foot long (haven't weighed it yet) . I also have some pure lead. Not knowing what else is in the auto body alloy, how would I mix this with pure lead to get a good casting alloy?
I also have about 25lbs of berm lead I could use. Usually load all pistol calibers for around 1000 fps (except 45ACP) which gives about 1,300 to 1,500 fps if used in rifles.

The berm lead usually comes out around 11 to 12 BHN.

What ratios should I use?

[bumpo628]

I think Tinners solder is 60% Tin, 40% Lead. For the following calculations, I am assuming that the range lead has about .25% tin, 2% antimony based on your 11-12 hardness measurement.

Mixing the 30% tin solder with pure lead:
1 oz solder + 3.5 lbs pure lead = alloy with 0.53% Tin
2 oz solder + 3.5 lbs pure lead = alloy with 1.03% Tin
3 oz solder + 3.5 lbs pure lead = alloy with 1.53% Tin
4 oz solder + 3.5 lbs pure lead = alloy with 2.00% Tin

Mixing the 30% tin solder with range lead:
1 oz solder + 6.5 lbs range lead = alloy with 0.53% Tin, 1.98% Antimony
2 oz solder + 4.5 lbs range lead = alloy with 1.05% Tin, 1.95% Antimony
3 oz solder + 4.0 lbs range lead = alloy with 1.58% Tin, 1.91% Antimony
4 oz solder + 4.0 lbs range lead = alloy with 2.00% Tin, 1.88% Antimony

Mixing the 60% tin solder with pure lead:
1 oz solder + 7.0 lbs pure lead = alloy with 0.53% Tin
2 oz solder + 7.0 lbs pure lead = alloy with 1.05% Tin
3 oz solder + 7.0 lbs pure lead = alloy with 1.57% Tin
4 oz solder + 7.0 lbs pure lead = alloy with 2.07% Tin

Mixing the 60% tin solder with range lead:
1 oz solder + 15 lbs range lead = alloy with 0.50% Tin, 1.99% Antimony
2 oz solder + 9.5 lbs range lead = alloy with 1.03% Tin, 1.97% Antimony
3 oz solder + 8.5 lbs range lead = alloy with 1.54% Tin, 1.96% Antimony
4 oz solder + 8.0 lbs range lead = alloy with 2.06% Tin, 1.94% Antimony

[waynzwld]

Thanks, I had no idea what the alloy was for those two.

[bumpo628]

Range lead can be just about anything. From what I've read around here, it usually doesn't have a hardness as high as yours. So, I figured it must have some antimony in there. WW usually has a hardness of about 12 and it has an average of 0.50% tin, 3% antimony.