Investment castings are rarely brass. They are generally some type of bronze, which can make filing, polishing, and engraving more problematic. I prefer sand cast yellow brass, but then I’m not building guns to sell, where the time to clean up these rough castings make it cost prohibitive. I also don’t get all upset when I uncover a small void, or pit, in these castings, because many of the originals had these defects as well.
Hungry Horse