I was casting with a new to me Lyman 3112991 I bought used. The mold looked OK, but it produced boolits with an odd surface texture I have never seen before (see pic). Is this rust in the cavities? Best course of action?
I will powder coat and gas check these and see if they shoot. Since I cast them out of pretty hard stuff (about half lino, half SOWW), they are only for target use so if they don't shoot well it is not a huge deal.