Lead:tin ratio

[ajc]

Hello, there.
I'm shooting BPCR in 40/65, and have a question about lead:tin ratios. I have a quantity of 20:1 lead to tin, and would like to add some tin to it to make it 16:1.
Can anyone tell me what the ratio of pure tin to 20:1 would be to make it 16:1?
I know it can't be much, but would like to eliminate the possibility of "bullet slump" I've been reading about.
Thanks,
AJC

[Larry Gibson]

20-1 means there is 8 ounces of tin in 10 lbs of lead. 16 - 1 alloy means there is 10 ounces of tin in 10 lbs of lead.

Or, for 20 lbs of 20-1 alloy lead add 4 more ounces of tin. Not exact to the nth degree but close enough.

[USSR]

Larry has it right. Close enough to 16-1.

Don

[ajc]

Thank you very much. I'm recovering from a stroke, and lost a few bites of memory. Just what I was looking for.
Art