mattd
07-08-2013, 01:08 PM
Man, I'm struggling to get this to work. My lee 44 mold was making undersized and out of round, .005-007, bullets. I think it's an alignment pin issue. I've been playing with the pins, as well as lapped one of the 2 cavities. Now I get .003-.004 out of round bullets and the ones from the lapped cavities come out .432-.436. Thought I could size them to .431 and life would be good, so I pan lubed em and waited for the sizing die.
A week later I got the lee 430 sizer and honed it out to .431, verified with a soft slug. Thought I would pass the bullets thru and finally have something that didn't lead. But I got hardly any resistance going thru the sizer. Measured and, except at the seams where they did size, they are undersized - .4295 - .431.
Casted a few more and measured an hour after the pour and they are big - .432-.436. So I guess I'm suffering from shrinkage. Up to .006!!? Measured some 40s that came out of the same batch. Previous they were .401, perfect. Now they are .400, too small.
Is shrinkage something you have to allow for? So I have to lap my cavities to .434+, wait a week and then size?
Alloy is 50% #9 mag shot 50% lead mixed then 2% pewter added.
A week later I got the lee 430 sizer and honed it out to .431, verified with a soft slug. Thought I would pass the bullets thru and finally have something that didn't lead. But I got hardly any resistance going thru the sizer. Measured and, except at the seams where they did size, they are undersized - .4295 - .431.
Casted a few more and measured an hour after the pour and they are big - .432-.436. So I guess I'm suffering from shrinkage. Up to .006!!? Measured some 40s that came out of the same batch. Previous they were .401, perfect. Now they are .400, too small.
Is shrinkage something you have to allow for? So I have to lap my cavities to .434+, wait a week and then size?
Alloy is 50% #9 mag shot 50% lead mixed then 2% pewter added.