CW When buying a drill for GC removal do you get one at the full dia of the bullet or a thousandth under?
I'm not CW, nor am I as brave - I tried a twist-drill once and it gave me the willies - wanted to suck the mould up the drill.
I found a chucking reamer on eBay pretty cheap which cut .3594" for my NOE 360-180 WFN, which gives me a bit over .360" as cast on the rear/driving band. One pass through the sizing die and it's all the same. I noticed on my Arsenal moulds, that when I request a slightly larger diameter, the rear band is bigger than the others and it has worked beautifully.
While we're talking about machining aluminum, I'll share a tip my dad shared with me for use on aluminum. He was a tool & die maker for 40 years and was capable of some amazing stuff. He told me to load the flutes of a drill or reamer with Crisco (any shortening) and it will trap chips which might otherwise get drug along the cut surface and make it ugly, or worse - get between the drill or reamer and the side of the hole and make the hole bigger than you wanted. It also serves as a lube. On a straight-flute reamer, the chips aren't carried up and out, so the Crisco works nicely for the minimal, slow hand-work that I do.