Difference between Lyman 575213 molds?

[Rlevin]

What are the differences between a 575213HM, 575213AV, 575213OS, and a 575213AV molds?Russ LevinBerdan C2

[Ron/The Old Reb]

The OS stands for old style, like the original Civil War Minnie. If you call Lyman at 1-800-225-9626 I'm sure that their customer rep can answer your question. I have called them several times with questions about their products.