I've been casting for 6 years or so for pistols using WW + 2% Tin at 750 degrees. My cast booits always came out over the size I needed.
I decided to casting for a Marlin 336 XLR in 30-30 (12 twist) and the barrel slugs at .3085". The plan was to cast, powder coat and size .311". I bought a Lee 309-170 & 309-150 and cast with the 309-170 mold today using 50/50 WW & Pure PB + 2% tin.
The boolits dropped at .309" exactly. If I powder coat to get the additional .002" needed, will I still get the same accuracy as if the boolits cast at .311", powder coat (adds .001-.002") and size to .311"?
Just thinking and wondering (if I need to lap my mold).