[eludwig]

As others have mentioned, a centrifugal casting machine would have really helped here. I took quite a bit of jewelry making in college and all the lost wax casting we did was done this way. The force of the metal filling the mold at extremely high speeds gets rid of most, if not all, of the impurities/inconsistencies.

Wind up the machine, melt the metal in a small crucible, drop the pin and duck (lol). I was once sprayed by a small stream of molten brass at +/- 1700 degrees (poor mold with thin wall, later fixed and recast) and still have a scar 40 years later to prove it.

[hakfoo]

If you can find a dental lab, the sort that makes crowns and bridges, they'll have this infrastructure, or at least they used to in the 2000s and before. My father worked at such a lab, and occasionally the dentists who owned it would ask him to cast wedding rings (no doubt made from the scrap gold leftover from regular work).