So I noticed something about my Lyman Molds

[Colorado4wheel]

I have two 4 cavity molds for 9mm. While sizing bullets I noticed that only 1/2 the bullet on many rounds were getting sized. I also noticed that on both my molds one side of my mold was shinny metal the other side had a dull patina. I am color blind but I don't think it was red. I decided to get rid on any patina with a little CLR and also scrub the mold with some barkeepers helper. I really got a lot of **** off the mold. I know it was seasoning but it was uneven. I then got them nice and hot and they look much better and the bullets look a lot rounder. Sizing lookes like it's touching the entire bullet now.

[MikeS]

I'm curious, you said you have 2 moulds, were they both dirty only on one half? If so, were they both dirty on the same side of the mould? If you got the moulds both at the same time (I'm assuming they're used moulds?), from the same source, you might want to check, and see if the mould numbers are matched (not the boolit number, but the mould number, the one that's on both blocks of the set), as it almost sounds like the 2 moulds were disassembled together at some time in their history, and then reassembled wrong. I could (and probably am) totally wrong, that's just the thought that popped into my head while reading your post.

It's amazing just how much dirt can be on a mould! I bought a 4 cavity SAECO mould on eBay that the seller said had no markings on it. It was really dirty, and after cleaning it, the sprue plate clearly said "SAECO Custom Precision No. 130"

[Iron Mike Golf]

Careful with Barkeeper's Helper. It's got acid in it. Great if you want to strip off the bluing. Like you saw, get them nice and hot and they blue back up. Thing is, acid will enlarge any pits you have, especially if you let them sit.

[Colorado4wheel]

I polished the inside of all the cavities today with some bullets and Bar Keepers Helper. I rinsed often. No etching. The bullets now fall out of the molds easy. They are round and even. Much better. I think I had some rusty build up in the bluing.